Computer System

All of the components of a computer system can be summarized with the simple equations.

COMPUTER SYSTEM = HARDWARE + SOFTWARE + HUMANWARE

·         Hardware = programs:

Software gives “intelligence” to the computer.

·         Human ware =User

Hardware

The physical parts of the computer, which can be seen and touched is known as hardware. It is just the mechanical parts of the Computer. All the devices attached to the Computer system like: Mouse, Monitor, CPU, Motherboard, Hard Disk, are Hardware. It includes all the components used to make the computer. It also includes the cables, connectors and computer peripherals.

Software:

Software, simply are the computer programs, the instructions given to the computer in the form of a program is called Software. Software is the set of programs, which are used for different purposes. All the programs used in computer to perform specific task is called software.

TYPES OF SOFTWARE

Computer Software is basically categorized into three types:

1.      System Software

2.      Application Software

3.      Programming Language & Scripting

1.      System software:

The software that control and direct the operation of the computer hardware is called system software is the collection of the programs written for computer, which allows the user to work on different program.

The system software consists of Operating system and utility software.

a)      Operating system software:

An operating system is a set of programs that controls and supervises a computer system and provides services to computer users. Operating system software controls overall activities of the computer. It acts as an interface between a user, program and the hardware. DOS, UNIX, XENIX, Windows are the examples of operating system.

b)     Utility software:

The software, which help the users to manage fi8les & folders, checking viruses, keeping PC healthy and system setting is called Utility Software. These are also the software tools which help to users while preparing programs. PC TOOLS, Scandisk, Disk Defragmenter, Norton Antivirus, Language Processors (Assembler, Compiler…..)are the examples of utility Software.

Language processors:

            The programs that translate the program written in high level and low level language to machine codes are called language processors.

Assembler:      It translates the programs written in low level language (assembly) to machine code.

Compliers:      It translates the programs written in high level language to machine codes. The complier translates the whole programs at a time that makes the execution faster.

Interpreter:    it also translates the program written in high level language to machine codes. Unlike compiler, it translates a single statement of a program at a time. Due to this it is easier to locate errors and debugging becomes easier.

2.      Application software:

The software used for special purpose (specific task) written in a specific language is known as Application Software. It also may be defined as software that acts as interface between the user and the system software to allow the user to perform specific tasks. These programs perform certain task with respect to related program. Basically, there are two types of Application Software:

a)      Package Software

This software is the set of the pre-written programs by another person or group and made available to computer users. Many kinds of related works can be performed by using any required software. Ms. Word, Ms. Ms. Access, Adobe PageMaker, AutoCAD are the examples of Package Software.

b)      Tailored or Custom Software

The tailored software are  used to perform the specific tasks only like Accounting, Super Market Billing, Mark sheet Preparation, Inventory Control etc .They are developed on demand of the clients, GMACC, Point of Sale, MEDI-PRO, TALLY etc. are the example of Tailored Software.

3.      Computer Programming Language & Scripting:

A language is a set of codes, which are used to write the programs. There are basically tow levels of programming languages. These are:

a)      Low Level Language:

i)        Machine Level language:

This is computer. Language. Computer understands information composed of only zero (0s) and ones (1s) and hence it uses binary digits for its operation. Programs, written in machine language only understood by the computer. The programming in this language is highly complicated. So, only software experts and only one personnel related to inner system can program in this language. These program codes or statements can be loaded directly into the computer’s memory. Today, programs are written in special programming language, but these programs must still a translated into the machine language before the program can be executed.

Assembly language:

      The writing a programs in machine language is very difficult, tiresome and boring job for a programmer. To solve this problem and facilitate programmer, easily understandable languages have been developed. Assembly language is one of them. Programs can easily be written in alphanumeric symbols instead of Os and 1s. Meaningful and easily rememberable symbols are selected for this purpose. For example, ADD for addition, SUB for subtraction, CMP for comparison etc. such symbols are known as mnemonics. A program written in mnemonics is called assembly language program. The    writing of programs in assembly language is easier and faster as compared to the writing of programs in   a machine language. However, programming in this language must be translated into machine language before the program can be executed. An assembler is a program, which converts these languages in to the machine code. So it is also sometimes called assembly language

b)     High level language :

These types of language are written in English language with set of rules, called syntax. Thus, it is easier to program then the other languages. These are easy to write, read and understand. Mistakes can be easily found and corrected in this language. Programs in this language also must be translated into machine language before the program can be executed. A compiler is a program, which translates into binary digits (I. e. machine language). COBOL) (Common Business Oriented Language), FORTRAN (FORmula TRAnslation), BASIC (Beginner’s All-purpose Symbolic Instruction Code), C, C++ etc. are the examples of High Level Language. The advantages of high-language are:

i.                    They are easier to learn as compared to assembly languages.

ii.                  They make programs easier and faster to write

iii.                Provide better documentation.

iv.                 The programmers are portable, i.e. they will run on any co9mpyter, which has a similar compiler.

BASIC:  It is a group of similar high-level programming languages whose name is derived from the words Beginners All purpose Symbolic instruction Code. BASIC was developed in the mid 1960s. It is a simple programming language, is easy to learn. It allows easy modification of programs.

FORTRAN:  It is the short form of FORmula TRANsiation. It is the first high-level computer language developed over the period 1954 to 58. It is especially used in the field of science and engineering. FORTRAN is a structured language.

C: C is a  general-purpose high-level programming language. It was developed by Dennis M. Ritchie in 1970’s. It is used to write any kinds of       operating system and application software.

C++: The C++ is a superset of C language. It is an object oriented programming Linage. It is an advance form of c and used to write various programs.

Visual Basic: Visual Basic is a very powerful program developing tools (not a pure programming language) that is especially used to design windows based programs. It was developed by Microsoft. Corporation, USA.

There are lots of other programming languages like java, c#, SQL etc. used in specific purposes.

Human ware/Live ware:

            Person, who operates (handles) computer and its periphery, is known as Human ware. It is also sometimes called user /Operator. A Computer is a totally user dependent device. It does not have its own brain, so it cannot work itself. So, a set of sequenced instructions is the soul and the user is the heart of the computer system.