Lila Ram Paudel: Computer fundamentals Objective & Subjective Quest...

Lila Ram Paudel: Computer fundamentals Objective & Subjective Quest...: Which of the following languages is more suited to a structured program?                 A.PL/1                 B.FORTRAN           ...

Computer fundamentals Objective & Subjective Question- Answers

Which of the following languages is more suited to a structured program?

                A.PL/1

                B.FORTRAN

                C.BASIC

                D.PASCAL*

                E.None of the above

A computer assisted method for the recording and analyzing of existing or hypothetical systems is

                A.Data transmission

                B.Data flow*

                C.Data capture

                D.Data processing

                E.None of the above

The brain of any computer system is

                A.ALU

                B.Memory

                C.CPU*

                D.Control unit

                E.None of the above

What difference does the 5th generation computer have from other generation computers?

                A. Technological advancement*

                B. Scientific code

                C. Object Oriented Programming

                D.All of the above

                E.None of the above

Which of the following computer language is used for artificial intelligence?

                A. FORTRAN

                B. PROLOG*

                C. C

                D.COBOL

                E.None of the above

The tracks on a disk which can be accessed without repositioning the R/W heads is

                A.Surface

                B.Cylinder*

                C.Cluster

                D.All of the above

                E.None of the above

Which of the following is the 1's complement of 10?

                A.01*

                B.110

                C.11

                D.10

                E.None of the above

A section of code to which control is transferred when a processor is interrupted is known as

                A.M*

                B.SVC

                C.IP

                D.MDR

                E.None of the above

Which part interprets program instructions and initiate control operations.

                A.Input

                B.Storage unit

                C.Logic unit

                D.Control unit*

                E.None of the above

The binary system uses powers of

                A.2*

                B.10

                C.8

                D.16

                E.None of the above

A computer program that converts assembly language to machine language is

A.      Compiler

B.      Interpreter

C.      Assembler*

D.      Comparator

E.      None of the above

The time required for the fetching and execution of one simple machine instruction is

A.      Delay time

B.      CPU cycle*

C.      Real time

D.      Seek time

E.      None of the above

               

The time for which a piece of equipment operates is called

A.      Seek time

B.      Effective time*

C.      Access time

D.      Real time

E.      None of the above

               

Binary numbers need more places for counting because

A.      They are always big numbers

B.      Any no. of 0's can be added in front of them

C.      Binary base is small*

D.      0's and l's have to be properly spaced apart

E.      None of the above

Which access method is used for obtaining a record from a cassette tape?

A.      Direct

B.      Sequential*

C.      Random

D.      All of the above

E.      None of the above

 Any type of storage that is used for holding information between steps in its processing is

A.      CPU

B.      Primary storage

C.      Intermediate storage*

D.      Internal storage

E.      None of the above

A name applied by Intel corp. to high speed MOS technology is called

A.      HDLC

B.      LAP

C.      HMOS*

D.      SDLC

E.      None of the above

A program component that allows structuring of a program in an unusual way is known as

A.      Correlation

B.      Coroutine*

C.      Diagonalization

D.      Quene

E.      None of the above

The radian of a number system

A.      Is variable

B.      Has nothing to do with digit position value

C.      Equals the number of its distinct counting digits*

D.      Is always an even number

E.      None of the above

The section of the CPU that selects, interprets and sees to the execution of program instructions

A.      Memory

B.      Register unit

C.      Control unit*

D.      ALU

E.      None of the above

Which type of system puts the user into direct conversation with the computer through a keyboard?

A.      Real time processing

B.      Interactive computer*

C.      Batch processing

D.      Time sharing

E.      None of the above

The term referring to evacuating the content of some part of the machine is known as

A.      Dump*

B.      Enhancement

C.      Down

D.      Compiler

E.      None of the above

A single packet on a data link is known as

A.      Path

B.      Frame*

C.      Block

D.      Group

E.      None of the above

The process of communicating with a file from a terminal is

A.      Interactive

B.      Interrogation*

C.      Heuristic

D.      All of the above

E.      None of the above

A common boundary between two systems is called

A.      Interdiction

B.      Interface*

C.      Surface

D.      None of the above

The examination and changing of single bits or small groups of his within a word is called

A.      Bit

B.      Byte

C.      Bit manipulation*

D.      Bit slice

E.      None of the above

Which computer has been designed to be as compact as possible?

A.      Mini

B.      Super computer

C.      Micro computer*

D.      Mainframe

E.      None of the above

Which method is used to connect a remote computer?

A.      Device

B.      Dialup*

C.      Diagnostic

D.      Logic circuit

E.      None of the above

How many bit code is used by Murray code for TELEPRINTER machines.

A.      4

B.      5*

C.      9

D.      25

E.      None of the above

The symbols used in an assembly language are

A.      Codes

B.      Mnemonics*

C.      Assembler

D.      All of the above

E.      None of the above

The 2's complement of a binary no. is obtained by adding.....to its 1's complement.

A.      0

B.      1*

C.      10

D.      12

E.      None of the above

A systems programming language for microcomputers in the Intel family is

A.      PL/C

B.      PL/CT

C.      PL/M*

D.      PLA

E.      None of the above

A datum that indicates some important state in the content of input or output is

A.      Sequence

B.      Sentinel*

C.      SIO

D.      Sibling

E.      None of the above

Which is a non-standard version of a computing language?

A.      PROLOG

B.      APL

C.      Army*

D.      PL/1

E.      None of the above

Which of the following is still useful for adding numbers?

A.      EDSAC

B.      ENIAC

C.      Abacus*

D.      UNIVAC

E.      None of the above

The average time necessary for the correct sector of a disk to arrive at the read write head is _____

A.      Down time

B.      Seek time

C.      Rotational delay*

D.      Access time

E.      None of the above

A number that is used to control the form of another number is known as

A.      Map

B.      Mask*

C.      Mamtossa

D.      Marker

E.      None of the above         

A general purpose single-user microcomputer designed to be operated by one person at a time is

A.      Special-purpose computer

B.      KIPS

C.      M

D.      PC*

E.      None of the above

ASCII stands for

A.      American standard code for information interchange*

B.      All purpose scientific code for information interchange

C.      American security code for information interchange

D.      American Scientific code for information interchange

E.      None of the above

Which device of computer operation dispenses with the use of the keyboard?

A.      Joystick

B.      Light pen

C.      Mouse*

D.      Touch

E.      None of the above

The microcomputer, Intel MCS-80 is based on the widely used Intel

A.      8080 microprocessor*

B.      8085 microprocessor

C.      8086 microprocessor

D.      8082 microprocessor

E.      None of the above

Which is a machine-oriented high-level language for the GEC 4080 series machines.

A.      LOGO

B.      SNOBOL

C.      Babbage*

D.      ALGOL

E.      None of the above

A program that is employed in the development, repair or enhancement of other programs is known as

A.      System software

B.      Software tool*

C.      Applications program

D.      Utility program

E.      None of the above

Any storage device added to a computer beyond the immediately usable main storage is known as

A.      Floppy disk

B.      Hard disk

C.      Backing store*

D.      Punched card

E.      None of the above

Which output device is used for translating information from a computer into pictorial form on paper.

A.      Mouse

B.      Plotter*

C.      Touch panel

D.      Card punch

E.      None of the above

The list of coded instructions is called

A.      Computer program*

B.      Algorithm

C.      Flowchart

D.      Utility programs

E.      None of the above

1. UNIVAC is Universal Automatic Computer, There are no computers with the name as in other options. UNIVAC was the first general purpose electronic digital computer designed for commercial use, produced by Universal Accounting Company of John Mauchly and J.P.Eckert in 1951.

2. CD-ROM stands for Compact Disk Read Only Memory, There are no objects with the name as in other options. CD-ROM is a non-volatile optical data storage medium using the same physical format as audio compact disk, readable by a computer with a CD-ROM drive. The standard 12 cm diameter CD-ROM store about 660 megabytes.

3. ALU is Arithmetic Logic Unit, ALU is a unit in Central Processing Unit in a computer system that is responsible for arithmetic calculations and logical operations. Apart from ALU, the CPU contains MU (Memory Unit) and CU (Control Unit).

4. VGA is Video Graphics Array,  VGA is a type of Graphics Adapter. Graphic Adapter is an electronic board that controls the display of a monitor. This device helps the motherboard to work with the monitor and in VGA and SVGA the last letter ‘A’ stands for ‘Array’ whereas in MDA, CGA, MCGA the last letter ‘A’ stands for ‘Adapter’.

5. IBM 1401 is  Second Generation Computer,  IBM 1401 is a Second Generation Computer and is the first computer to enter Nepal in 2028 BS for census. Government of Nepal had brought this computer on rent and later purchased for data processing in Bureau of Statistics. After this computer, another ICL 2950/10, a British computer, was purchased by the fund of UNDP and UNFPA for the census of 2038 BS is second computer in Nepal.

6. MSI stands for Medium Scale Integrated Circuits, After the invention of IC chips the development of computers plunged into next phase. Small Scale Integration and Medium Scale Integration (SSI and MSI) were used in third generation of computers and Large Scale Integration and Very Large Scale Integration (LSI and VLSI) are being used in fourth generation of computers. People are now expecting ULSI (Ultra Large Scale Integration) Circuits to be used for fifth generation computers.

7. The capacity of 3.5 inch floppy disk is  1.44 MB, Microfloppy disks (3.5 inch) if it is high density (MF2HD) can store 1.44 MB and if it is low density (MF2DD), it can store 720 KB. Mini Floppy disks (5.25 inch) if it is high density (MD2HD) can store 1.2 MB and low density (MD2DD) stores 360 KB of data.

8. The first computer introduced in Nepal was IBM 1401, IBM 1401, a second generation computer was brought in Nepal by the Government of Nepal paying One Lakh and twenty five thousands per month to use in the census in 2028 B.S. Before this computer, Nepal was using a calculating device called Facit for statistical tasks.

9. WAN stands for Wide Area Network, There are three different classes of computer network namely, Local Area Network (LAN) that covers a small geographical area such as a room, a building or a compound; Metropolitan Area Network (MAN) that has a citywide coverage; and Wide Area Network (WAN) that covers the whole globe or beyond the globe.

10. MICR stands for Magnetic Ink Character Reader, Explanation: MICR (Magnetic Ink Character Reader) is kind of scanner that can scan and identify the writing of magnetic ink. This device is used in banks to verify signatures in Checks.

11. EBCDIC stands for Extended Binary Coded Decimal Interchange Code, EBCDIC is an 8-bit binary code for larger IBMs

primarily mainframes in which each byte represent one alphanumeric character or two decimal digits. 256 characters can be

coded using EBCDIC.

12. BCD is Binary Coded Decimal, BCD is a binary coded notation in which each of the decimal digits is expressed as a 8-bit

binary numeral. For example in binary coded decimal notation 12 is 0001 0010 as opposed to 1100 in pure binary.

13. ASCII stands for American Standard Code for Information Interchange,  ASCII is a code which converts characters

letters, digits, punctuations and control characters such as Alt, Tab etc – into numeral form. ASCII code is used to

represent data internally in micro-computers. ASCII codes are 7 bits and can represent 0 to 127 and extended ASCII are 8

bits that represents 0 to 255.

14.EDSAC is first generation of computer: IBM-1401, CDC-1604 is second generation computer. ICL-2900 is a fourth generation

computer. EDSAC is important in the development of computer since it was the first computer to use John von. Neumann’s

Stored Program Concept. It used 3000 vacuum tubes and computers with vacuum tubes are of first generation computers.

15. Chief component of first generation computer was Vacuum Tubes and Valves, Transistors were used for second generation

computers and integrated circuits in third generation. First generation computers used vacuum tubes and valves as their main

electronic component. Vacuum Tubes were invented by Lee DeForest in 1908.

16. FORTRAN is Formula Translation, FORTRAN (Formula Translation) is one of the earlier High Level programming languages used

to write scientific applications. It was developed by IBM in 1956.

17. EEPROM stand for Electrically Erasable Programmable Read Only Memory There are three types of ROM namely, PROM, EPROM and EEPROM. PROM can’t be reprogrammed, EPROM can be erased by exposing it in high intensity ultraviolet light and EEPROM can be erased and reprogrammed electrically. It is not needed to be removed from the computer to be modified.

18. Second Generation computers were developed during 1956 to 1965. Second generation computers used transistors as their

main electronic component. Transistor was invented by Bell Lab Scientists John Burdeen, Walter Brattain and William Shockley

in 1947 and won the Nobel Prize in 1956 but it was not used in computers till 1956. The second generation continued until the implementation of IC chips invented by Jack Kilby in Texas Instruments in 1958.

19. The computer size was very large in First Generation. It is obvious that computers developed with more power, eliability,

speed and smaller sizes due to the enhancement of technology. First generation computers used 1000s of vacuum tubes that

required lot of space made them gigantic in size. Single transistor could replace 1000 vacuum tubes and a single IC chip replaced 1000s of transistors made computers smaller and more speedy.

20. Microprocessors as switching devices are for Fourth Generation computers. Microprocessors further revolutionized the development of computers. Personal microcomputers were possible due to the microprocessors. The first microprocessor called

Intel 4004 was developed by American Intel Corporation in 1971. Microprocessors are used in the computers of fourth generation computers.

Processor

Similarities and differences between the Pentium 4 and the Celeron chips :

Celeron processor is a good and cheaper alternative to Pentium II, Pentium III and Pentium 4 microprocessors when the top performance is not required, and microprocessor and desktop price is important. The Celeron processors are based on the same core as more expensive Pentium-branded processors, but usually lack in some features such as L2 cache size and bus speed. Since the Celeron processor family spans three generations of x86 microprocessors, the differences between Celeron and Pentium processors vary depending on the generation.

•             Core - The Celeron chip is based on a Pentium 4 core.

•             Cache - Celeron chips have less cache memory than Pentium 4 chips do. A Celeron might have                   128 kilobytes of L2 cache, while a Pentium 4 can have four times that. The amount of L2 cache                     memory can have a big effect on performance.

•             Clock speed - Intel manufactures the Pentium 4 chips to run at a higher clock speed than Celeron                chips. The fastest Pentium 4 might be 60 percent faster than the fastest Celeron.

•             Bus speed - There are differences in the maximum bus speeds that the processors allow. Pentium                   4s tend to be about 30 percent faster than Celerons.¬

When you sort all this out and compare the two chips side by side, it turns out that a Celeron and a Pentium 4 chip running at the same speed are different beasts. The smaller L2 cache size and slower bus speeds can mean serious performance differences depending on what you want to do with your computer. If all you do is check e-mail and browse the Web, the Celeron is fine, and the price difference can save you a lot of money. If you want the fastest machine you can buy, then you need to go with the Pentium 4 to get the highest clock speeds and the fastest system bus.

Deference Between Pentium and core processor

The difference between a Pentium 4 and a duo core processor is that a Pentium four only has one mode for a processor thus making it slower, the duo core processor has 2 modes for processing.

Pentium History

Intel debuted the original Pentium processor in 1993, and the device bears little similarity to the ever-more-powerful processors that would follow. The successive Pentium Pro, Pentium 2, Pentium 3 and Pentium 4 processors were among the most popular processors of the 1990s, with competition from AMD devices. Other processors using the Pentium name included the Pentium D, Pentium M and newer Pentium Dual-Core families. The processors have seen use in desktop as well as laptop machines.

Core History

Intel introduced the Core brand in 2006 as a replacement for the Pentium M line of processors, and the initial devices shared much of the same technology with the current Pentium-branded offerings. Follow-ups to the original include the Core Solo, Core Duo,  Core 2 Quad, Core i3, Core i5 and Core i7 processor families. Starting with the Core 2, Core products were available for both laptop and desktop computers.

Pentium vs Core i3

The Pentium is probably the most popular line of Intel processors but it has been cast of the limelight due to the appearance of the newer Core line. But with the introduction of the Pentium G6950 and the Core i3 5xxx series, which are both Clarkdales, the need to identify the differences between them arises again. To be quick about it, the Pentium is basically identical to the i3 but with certain features disabled to differentiate it from the i3 and make it fit the price range of a low-end model.

For starters, the Pentium only has 3MB of L3 cache memory while the i3 has 4MB. More cache directly translates to lesser main memory accesses, which is much slower compared to cache memory. Controllers on the Pentium are also slower compared to those found on the i3. The memory controller of the i3 supports 1066Mhz and 1333Mhz modules while the Pentium would supports 1066Mhz and would automatically scale down the 1333Mhz module you put in. This is also the case when it comes to the graphics controller of the both processors. Whereas the i3 graphics controller runs at 733Mhz, that of the Pentium is only able to run at 533Mhz.

Also on the integrated graphics aspect, the Pentium lacks support for the Intel Clear Video HD Technology. This technology covers the playback of video and includes such features as dual video decode for Blu-ray, deep color and extended gamut, and other high-end options for video playback. All this can be found on the i3.

Lastly, hyper-threading is disabled in the Pentium but not in the i3. Hyper-threading allows the operating system to see each core as two virtual cores. While the Pentium is seen by the operating system as having two cores, the i3 is seen as having four due to hyper-threading. Hyper-threading is known to provide performance improvements in applications that are optimized for multi-threading, where the tasks are broken up and pieces are assigned to different cores.

computer memory & Software Overview

Memory

Memory refer to computer components, devices and recording media that retain digital data used for computing for some interval of time. Computer memory includes internal and external memory.

          Internal memory

        The internal memory is accessible by a processor without the use of the computer input-output channels. It usually includes several types of storage, such as main storage, cache memory, and special registers, all of which can be directly accessed by the processor. 

• Cache memory : A buffer, smaller and faster than main storage, used to hold a copy of instructions and data in main storage that are likely to be needed next by the processor and that have been obtained automatically from main storage.
• Main memory (Main Storage) : addressable storage from which instructions and other data may be loaded directly into registers for subsequent execution or processing.
  
  Storage capacity of the main memory is the total amount of stored information that the memory can hold. It is expressed as a quantity of bits or bytes. Each address identifies a word of storage. So the capacity of the main memory depends on the number of bits allowed to address. For instance, a computer allows also 32-bit memory addresses; a byte-addressable 32-bit computer can address 2³²  = 4,294,967,296 bytes of memory, or 4 gigabytes (GB). The capacity of the main memory is 4 GB.

The main memory consists of ROM and RAM.

Random Access Memory (RAM):

The primary storage is referred to as random access memory (RAM) because it is possible to randomly select and use any location of the memory directly store and retrieve data. It takes same time to any address of the memory as the first address. It is also called read/write memory. The storage of data and instructions inside the primary storage is temporary. It disappears from RAM as soon as the power to the computer is switched off.

 Read Only Memory (ROM):

There is another memory in computer, which is called Read Only Memory (ROM). Again it is the ICs inside the PC that form the ROM. The storage of program and data in the ROM is permanent. The ROM stores some standard processing programs supplied by the manufacturers to operate the personal computer. The ROM can only be read by the CPU but it cannot be changed. The basic input/output program is stored in the ROM that examines and initializes various equipment attached to the PC when the switch is made ON.

          External Memory

        The external memory holds information too large for storage in main memory. Information on external memory can only be accessed by the CPU if it is first transferred to main memory. External memory is slow and virtually unlimited in capacity. It retains information when the computer is switched off and is used to keep a permanent copy of programs and data.

• Hard Disk: is made of magnetic material. Magnetic disks used in computer are made on the same principle. It rotates with very high speed inside the computer drive. Data is stored on both the surface of the disk. Magnetic disks are most popular for direct access storage device. Each disk consists of a number of invisible concentric circles called tracks. Information is recorded on tracks of a disk surface in the form of tiny magnetic spots. The presence of a magnetic spot represents one bit and its absence represents zero bit. The information stored in a disk can be read many times without affecting the stored data. So the reading operation is non-destructive. But if you want to write a new data, then the existing data is erased from the disk and new data is recorded. The capacity of a hard disk is possibly 20 GB, 30 GB, 40 GB, 60 GB or more.
•  Floppy Disk: It is similar to magnetic disk discussed above. They are 5.25 inch or 3.5 inch in diameter. They come in single or double density and recorded on one or both surface of the diskette. The capacity of a 5.25-inch floppy is 1.2 mega bytes whereas for 3.5 inch floppy it is 1.44 mega bytes. The floppy is a low cost device particularly suitable for personal computer system.
•  Optical Disk : With every new application and software (includes sounds, images and videos) there is greater demand for memory capacity. It is the necessity to store large volume of data that has led to the development of optical disk storage medium. There are two commonly used categories of optical disks: CD with the approximate capacity of 700MB and DVD with the approximate capacity of 4.7GB.
• Memory Stick (Flash card, flash drive):  a removable flash memory card format, with 128MB, 256 MB, 512 MB, 1 GB, 2 GB , 4 GB or more capacities.

Input-Output Devices

A computer is only useful when it is able to communicate with the external environment. When you work with the computer you feed your data and instructions through some devices to the computer. These devices are called Input devices. Similarly the computer after processing, gives output through other devices called output devices.

Common input and output devices are: Speakers, Mouse, Scanner, Printer, Joystick, CD-ROM, Keyboard, Microphone, DVD, Floppy drive, Hard drive, Magnetic tape, and Monitor. Some devices are capable of both input and output.    

    

 Input Devices

        Input devices are necessary to convert our information or data in to a form which can be understood by the computer. A good input device should provide timely, accurate and useful data to the main memory of the computer for processing followings are the most useful input devices.

Keyboard: -

This is the standard input device attached to all computers. The layout of keyboard is just like the traditional typewriter. It also contains some extra command keys and function keys. It contains a total of 101 to 104 keys. You must press correct combination of keys to input data. The computer can recognize the electrical signals corresponding to the correct key combination and processing is done accordingly.

Mouse: -

 Mouse is an input device that is used with your personal computer. It rolls on a small ball and has two or three buttons on the top. When you roll the mouse across a flat surface the screen censors the mouse in the direction of mouse movement. The cursor moves very fast with mouse giving you more freedom to work in any direction. It is easier and faster to move through a mouse.

Scanner:

 The keyboard can input only text through keys provided in it. If we want to input a picture the keyboard cannot do that. Scanner is an optical device that can input any graphical matter and display it back.

          Output Devices

• Monitor: The most popular input/output device is the monitor. A Keyboard is used to input data and Monitor is used to display the input data and to receive massages from the computer. A monitor has its own box which is separated from the main computer system and is connected to the computer by cable. It can be color or monochrome. It is controlled by an output device called a graphics card. Displayable area measured in dots per inch, dots are often referred to as pixels. Standard resolution is 640 by 480. Many cards support resolution of 1280 by 1024 or better. Number of colors supported varies from 16 to billions
• Printer: It is an important output device which can be used to get a printed copy of the processed text or result on paper. There are different types of printers that are designed for different types of applications.

Buses

Bus is a subsystem that transfers data or power between computer components inside a computer or between computers. Bus can logically connect several peripherals over the same set of wires. Each bus defines its set of connectors to physically plug devices, cards or cables together. The buses are categorized depending on their tasks:

• ·         The data bus transfers actual data.
• ·         The address bus transfers information about where the data should go.
• ·         The control bus carries signals that report the status of various devices.

Programs and Programming Languages

Programs

        A computer program is an algorithm written for a computer in a special programming language. 

        Programming languages

A programming language is an artificial language that can be used to control the behavior of a machine, particularly a computer. It is defined through the use of syntactic and semantic rules, to determine structure and meaning respectively.

Programming languages are used to facilitate communication about the task of organizing and manipulating information, and to express algorithms precisely.

 There are large number of programming language in use. We can identify three type of programming languages : machine languages, assembly languages, high-level languages.

Machine Languages

        Machine code or machine language is a system of instructions and data directly executed by a computer's central processing unit. Machine code is the lowest-level of abstraction for representing a computer program. Instructions are patterns of bits with different patterns corresponding to different commands to the machine. Machine code has several significant disadvantages : very difficult for a human to read and write, a program written on one computer cannot run on a different computer, so it cannot be used to write large program or program intended to run on different machines.

Assembly Languages

        An assembly language is a low-level language for programming computers. It implements a symbolic representation of the numeric machine codes and other constants needed to program a particular CPU architecture.

 This representation is usually defined by the hardware manufacturer, and is based on abbreviations (called mnemonics) that help the programmer remember individual instructions, registers, etc. An assembly language is thus specific to a certain physical or virtual computer architecture.

A utility program called an assembler, is used to translate assembly language statements into the target computer's machine code.

Although assembly is more friendly than machine code, use of assembly offer several disadvantages, for instance, each type of computer has its own assembly language or programming assembly requires much time and effort.

Hence, assembly language is not use to write large programs. However, there are some computer application, such as in writing program that control peripherals, assembly is still a necessity.

High-level languages

        A high-level programming language is a programming language that, may be more abstract, easier to use, or more portable across platforms.

Examples: Pascal, C, Visual Basic, SQL, . . . .

Such languages often abstract away CPU operations such as memory access models and management of scope.These languages have been implemented by translating to machine languages.

There are two types of translators

Compiler is a program that translate source code from a high-level programming language to a lower level language (e.g., assembly language or machine language)

Interpreter is a program that translates and executes source language statements one line at a time.

Domain Analysis

Often the first step in attempting to design a new piece of software, whether it be an addition to an existing software, a new application, a new subsystem or a whole new system, is, what is generally referred to as "Domain Analysis". The more knowledgeable they are about the domain already, the less the work required. Another objective of this work is to make the analysts who will later try to elicit and gather the requirements from the area experts or professionals, speak with them in the domain's own terminology and to better understand what is being said by these people. Otherwise they will not be taken seriously. So, this phase is an important prelude to extracting and gathering the requirements.

Software Elements Analysis

The most important task in creating a software product is extracting the requirements. Customers typically know what they want, but not what software should do, while incomplete, ambiguous or contradictory requirements are recognized by skilled and experienced software engineers. Frequently demonstrating live code may help reduce the risk that the requirements are incorrect.

Specification

 Specification is the task of precisely describing the software to be written, possibly in a rigorous way. In practice, most successful specifications are written to understand and fine-tune applications that were already well-developed, although safety-critical software systems are often carefully specified prior to application development. Specifications are most important for external interfaces that must remain stable.

Software architecture

The architecture of a software system refers to an abstract representation of that system. Architecture is concerned with making sure the software system will meet the requirements of the product, as well as ensuring that future requirements can be addressed. The architecture step also addresses interfaces between the software system and other software products, as well as the underlying hardware or the host operating system.

Implementation (or coding)

 Reducing a design to code may be the most obvious part of the software engineering job, but it is not necessarily the largest portion.

Testing

Testing of parts of software, especially where code by two different engineers must work together, falls to the software engineer.

Documentation

An important (and often overlooked) task is documenting the internal design of software for the purpose of future maintenance and enhancement. Documentation is most important for external interfaces.

Classification of Computer Software

The software is divided to System Software and Application Software with each having several sub levels.

System software is the low –level software required to manage computer resources and support the production or execution of application program.

Application software is software program that perform a specific function directly for the end user.

System Software includes

• Operating Systems software
• Network Software : network management software, server software, security and encryption software, etc.
•  Database management software
• Development tools and programming language software: software testing tools and testing software, program development tools, programming languages software 
• Etc.

Application Software includes

• General business productivity applications : software program that perform a specific function directly for the end user, examples include : office applications, word processors, spreadsheet, project management system ,etc. 
•  Home use applications : software used in the home for entertainment, reference or educational purposes, examples include games, home education etc. 
• Cross-industry application software :  software that is designed to perform and/or manage a specific business function or process that is not unique to a particular industry, examples include professional accounting software, human resources management, Geographic Information Systems (GIS) software, etc. 
•  Vertical market application software : software that perform a wide range of business functions for a specific industry such as manufacturing, retail, healthcare , engineering, restaurant, etc. 
•  Utilities software : a small program that performs a very specific task. Examples include : compression programs, antivirus, search engines, font, file viewers, voice recognition software, etc.