Introduction To Computer System

Introduction To Computer System

What Is Computer System ?

In this introduction to computer system ,we will discuss in detail what is a computer system , technical features of the computer system , computer hardware , computer software , computer system architecture and other important topics related to the Computer system. 

A computer system is a digital electronic machine that can programmed to perform some operations as per the computer program instructions.

Computer System Block Diagram , Central Processing Unit

The computer system consist of both hardware and the software components . The computer hardware components are physical components mounted within the computer case and some are also connected externally.

The computer system needs to be directed to perform various user specified operations. And therefore , the computer system needs a program which directs the computer hardware . The computer program is also commonly referred to as software.

The introduction to computer system includes computer system organization and architecture and its technical features.

In this computer introduction you will also learn hardware components such as mother board , hard disk drive ( Disk Memory ) , power unit , Central Processing Unit ( CPU ) also referred to as micro-processor , Random Access Memory ( RAM ) , computer buses , cooling fans and other hardware components. 

Introduction To Computer System

Table Of Contents

What Is Computer System ?

Computer Definition

A  Computer system is defined as  a digital electronics  device  that  can  be programmed  to accept  some  inputs  in  terms of  data  , then process  this  data as per the program instructions   and  provide  the  Output  in  the  desired  format  that can be used for some meaningful  work.

Introduction To Computer System

  The computer user interacts with the application software and provides the input data . This data is processed by the computer system with the help of application software .

The application software in turn interacts with the operating system and the processed data or we can call program output is then sent to the output device.

The output device could be either a monitor , speaker , printer , storage device or any other output device.

What Is Computer System ?

Features Of The Computer System

Computer System Is Programmable

The computer system consist of both software components and hardware components.  The hardware components are physical parts that we can touch and interact. Whereas the software is essential to drive the hardware.

The computer program ( software ) is an essential component of every computer system which  directs the computer to performs various tasks.

Computer Software And Hardware Components
Computer Software And Hardware Components

The Computer system is  programmable. That  means ,  the computer will perform the task only as per the program instructions .

And therefore , the computer needs a program written in a programming language to execute a particular task on the computer system .

The Computer program directs the computer system through series of instructions. Each program instruction performs a specific part of the operation.

What Is Computer Program

What Is Computer Program ?

The software components are computer programs. The program consist of set of instructions that directs the computer system hardware components to perform the desired operations.

The computer programs are generally written using high level ( human readable ) programming language such as C , C++ , Java , Python and many more . 

However , a high level programs are first required to be converted into low level ( machine code ) instructions in binary that can be directly executed by the computer. This conversion is called program compilation.

The computer system interprets these program instructions and then performs the desired operations. The CPU executes the program instructions one by one.

What Is Computer Program ?

The Computer Accepts Input And Provides Output

The Computer Converts Raw Data Into Information

The Computer Systems are versatile machines and can be used to perform number of operations . 

For example , a company   might use the  computer system for managing employee database , customer database , inventory management , billing , record keeping , payroll processing , accounting and many such applications.

In order to use the computer system for any database operations , a DBMS  ( Database Management System ) software is required .

Data Processing
Data Processing

The computer system is also used to process the raw  data  and  produce the  information  that can be used for some meaningful purpose.

The information  can be used for some meaningful  work  such as decision making within an organization .

Computer System Is A Digital Machine

The Computer  is  a  digital  electronic  machine .  That means  , computer  can understand  and  execute  instructions  on  in  binary  which consist  of  only two numbers that  is  0  and  1 . The  binary  code  is also referred  as machine code  or machine language .

The computers central processing unit ( CPU ) is the brain of the computer system. The CPU is responsible to perform both arithmetical and logical operations.  

Programming Languages , Computer science Fields of Study
Program Compilation , CS Fields Of Study

However , the computers micro-processor ( CPU ) can understand and execute instructions only in machine code in Binary .

So  , it doesn’t really matter  in which  programming language you  write your program code because  eventually  ,  all computer programs  must be first converted  to  machine code in binary consisting of only 0 and 1.  

Why Computer Understands Binary 0 And 1 ?

Characteristics Of Computer System

characteristics of the computer

Automatic Working

The computers are extensively being used for automatic operations . The computer once programmed to perform some task can continue without any human intervention.

The artificial intelligence has further enhanced this capability for the computers. The computer can repetitively perform many operations in the automatic mode.

Operating Speed

The modern computers are armed with the latest microprocessor can execute billions of instructions within a fraction of a second. That gives huge processing power to the computer.

And therefore, the computer can be effectively used for performing complex operations with very high operating speed.

Accuracy Of Calculations

The computer can perform millions of complex calculations and take logical decisions as per the program instructions with remarkable accuracy.

However , the accuracy also depends upon the accuracy of the program instructions. The computer will produce wrong result if there are any mistakes into the program instructions.

This is often referred to as “Garbage In Garbage Out” ( GIGO ).

Computer Is Versatile

The computer is a truly versatile machine that can be used for many applications. The use of computer is now an essential part of every industry and profession we can possibly think of.

Apart from its applications in academics , the computers are everywhere. The computers are used by the students , teachers , musicians , doctors , engineers , accountants , police , armed forces and architects.

Both large scale and small scale companies are dependent upon the computers to manage their business operations.

Computer Is Reliable

The computers are the most reliable machines to perform multiple tasks without any mistake with the lightening speed.

And therefore , the computerized operations are the backbone of all top business corporations , global ecommerce giants such as Amazon , Reliance and for other companies.  

The computer system can also be programmed to enforce set of rules to ensure safety of the user and data security.

Computer Is Diligent

There are many business corporations and manufacturing companies that work day and night without any break. Such operations and production lines can be very well managed by the use of computers.

Depending upon the use, the computer hardware is specially tailor made to handle such prolonged operations.

Computer Has Memory

The computer system has both short term and long term memory . The business corporations that generate large volumes of data needs to be stored into the permanent storage devices for the future use.

The computer system with front end application software , a database management system ( DBMS ) and the database is essential to manage such large volumes of data.

For example , tech giants like Google , Facebook handle large volumes of data related to the millions of users across the globe.

Computer Needs Program

The computer is often said to be a dumb machine without any IQ. And therefore , the computer needs a set of instructions called a program.

A computer program is an essential component of every computer system. Each task and operation performed by the computer is completed as per the program.

The computer is not going to perform any task on its own unless it is directed by the computer program.

Components Of Computer System

The Computer system consist of four basic components Or Units . In terms of functionality , the computer system can be grouped in to four units . 

The Computer System Components are :

  1. Input Devices ( Input Unit ) .
  2. CPU ( Central Processing Unit ) .
  3. System Memory ( Memory Unit ) .
  4. Output Devices ( Output Unit ) .
Components Of Computer System

Input And Output Devises

Computer System Input Unit

The term “Input Unit ” ( Input Devises )  refers to the  input  provided   by the  user  by  using   any   input  device  such  as  keyboard  , mouse  , mike  , camera or any storage device in the form of input data.

The input data is operated and processed by the  Central Processing Unit ( CPU ) as per the program and sent to the output unit for further action.

Computer System Block Diagram
Computer Input And Output Devices

Computer System Output Unit

The term “Output Unit ” refers to the  output  provided   by the   computer CPU after processing the user data inputs  .

This output is then sent to the output  device such as monitor , printer , speaker   to  provide desired  output to  the  user. The output can also be stored on any storage device for future use.

The memory unit is an essential part of every computer system. The computer system needs memory to store the program instructions and the data before and after the processing.

The computer system memory unit consist of both temporary and permanent memory. The Random Access Memory ( RAM ) is the main memory where the operating loads the program for its execution.

The temporary memory RAM can store the data till the time the system is powered on . Whereas, the permanent memory ( disk memory ) can store the data even after the the system power is switched off. 

Computer System Memory Hierarchy

The computer  system  makes  the  use  of  different   types  of memories organized in a hierarchical manner  and together they are referred as memory unit. The arrangement of different types of memories is referred as memory hierarchy.

The computer memory unit consist of  different types of memories which  differ  in  capacity ,  access speed  ,  physical  size  and  the  cost  of the memory  . 

Computer Memory Hierarchy
Computer Primary And Secondary Memory

Each  of  the memory  is  optimally  used  in the computer system  depending upon its  access  speed  , size  and  proximity  to the  CPU . 

The computer system makes use of different types memory depending upon the functional requirements .

The  computer memory  is  mainly  divided  in to  two types  based on the  data  retention  by the computer memory when  power  is  switched  off  to  the  computer system.

Computer System Memory Types

The computer memories can be grouped into  two basic types depending upon the data retention by memory when system power supply is switched off .

If the memory retains the data without power supply, then it is referred as permanent memory . For example hard disk , pen drive are permanent memory ( Also referred as secondary memory ) .

The Random Access Memory ( RAM )  is the main system memory for a computer system . The RAM is a temporary memory because it retains the data only till the time , the  system power supply is on.

The data in the RAM is lost once the  system is switched off . And therefore main memory RAM is referred as temporary memory ( also referred as primary memory ).

Functions Of Computer

Program Execution

The program execution is the main function of the computer system. The computer system makes use of its hardware and software components to execute the program.

Various components such as memory ( RAM ) , CPU , input devices , output devices performs different functions together during the program execution.

Accept The Data From Input Devices

The computer system operates on the data as per the program instructions. The computer accepts the data through different types of input devices such as mouse , keyboard scanner and other input devices.

Store Data And Program In Memory

The computer stores the data and the program into its main memory RAM. The program is stored into the memory as set of instructions.

The CPU starts the program execution by fetching the data and instructions from the memory . The CPU sends the processed data back to the memory for the output devices.

Data Processing

The computers are extensively used for data processing jobs. The process converting the raw data into useful information is defined as data processing.

The data is processed as per the program instructions. For example , the monthly attendance data is converted into salary statements at the end of the month by using a payroll application software.

Send Output To Output Device

The output devices are used to send the result that can used by the user. The program output can either be sent to the monitor , printer , storage disks or any other output device.

Control All Operations

The computer system controls the operations of the software and hardware components. The control unit of the CPU ( central processing unit ) controls the operations of the entire computer system .

Types Of Computer Systems

Types Of Computer

Computer System Architecture

What is Computer System Architecture ?

In  computer engineering, the computer system  architecture is the conceptual design and fundamental operational structure of a computer system.

It is the technical drawings and functional description of all design components and  requirements . The system architecture defines the system performance parameters such as speed and interconnections .

Computer System Architecture

The System architecture can also be defined as the science and art of selecting and interconnecting hardware components to create computer system that meet  functional , performance  and cost goals.

And therefore , better system architecture will produce a better design and system performance.

Computer System Block Diagram

The Computer system consist of four basic components Or Units . In terms of functionality , the computer system can be grouped in to four  basic units . 

The Computer System Components are :

  1. Input Unit ( Input Devices ).
  2. Central Processing Unit ( CPU ) .
  3. System Memory Unit .
  4. Output Unit ( Output Devices ) .
Computer System Block Diagram

Computer Hardware

The  computer system  mainly  consist  of  hardware components  and  the  software components .   All  the  physical  components  inside  the computer cabinet  and  the  input  / output  gadgets  attached  to  the  computer  are  referred  as  hardware  components .

The hardware  components  inside the computer  cabinet  are referred  as  internal  components  such as  motherboard .The external  hardware components attached  to the computer  system  are also referred as peripheral  devices  such  as  keyboard , mouse , monitor  .

Computer System Hardware Components
Computer System Hardware Components

Computer Hardware Components

Computer System - Motherboard

The motherboard is the main printed circuit board ( PCB ) that is mounted inside a computer cabinet. The motherboard  is a junction for connecting some important internal components .

The components that are directly placed on the motherboard include microprocessor ( CPU ) , main memory RAM , Graphic card , sound card , north bridge and south bridge.

Computer System Motherboard

Computer System - Microprocessor

The central process ring unit ( CPU ) effectively functions as a brain of the computer system. 

The CPU performs arithmetic and logical operations and provides processing power of the computer system.

The CPU is mounted on the motherboard inside a processor socket which is a special slot  present on the motherboard. 

The processor chip firmly placed inside CPU socket  with help of liver locking mechanism.

A heat sink and a cooling miniature fan is placed on the top of the processor chip to protect the processor chip from excessive heat generated by the processor chip.

Processor Socket On Mother Board , Central Processing Unit

What Is CPU ? | How CPU Works ? | CPU Functions

The central processing unit ( CPU ) is also alternately referred to as microprocessor or processor .  The processor provides the processing power to the computer system .

The CPU performs number of vital functions . One of the the main function of the CPU is to execute the  computer program . 

The CPU executes the computer program by repetitively performing a machine cycle which is a basic operation of the processor . The machine cycle consist of four steps . These machine cycle steps are : 

What Is Central Processing Unit ?

The operating system loads the program instructions and associated data into the main system memory RAM . The CPU fetches the data and program instructions from the main memory .

The CPU executes the computer program by repetitively performing a machine cycle which is a basic operation of the processor . The machine cycle consist of four steps . These machine cycle steps are : 

Main System Memory

Random Access Memory ( RAM )

The computer system makes use of different types of memories . These different types of memories are organized into the system in order to optimize the CPU performance.

The main system memory RAM ( Random Access Memory ) modules are mounted inside special RAM slots on the motherboard . Each motherboard has fixed number of RAM slots .

The maximum permissible RAM size ( 4 GB , 8GB , 16 GB ) supported by the system depends  upon the system configuration and the type operating system  ( 32 Bit OR 64 Bit OS ).


Random Access Memory ( RAM )

System - Power Supply Unit

The computer system has a centralized power supply unit that provides electrical power supply to various internal components .

The desktop computer system power system is referred as SMPS which stands for Switched Mode Power Supply . The SMPS provides different voltage of power supply to different components through set of electric wires.

Computer Software

The computer software is a  set program instructions designed to perform a specific tasks . A computer program is written  in  computer programming language such  as  C , C++ , Java  , python and so many other languages .

The  computer system makes use of two types of software .

The System software is used by the system itself manage and control the system hardware components. The operating system communicates with the hardware components through system software . 

The System software includes Operating System ( OS ) ,device drivers and other system utility programs . The application software  are used by the computer user to perform various tasks on the system. The commonly used application software includes  MS Word , Excel .

Computer System Software Components

Computer System Software

What Is System Software ?

In computer system architecture , the System Software  is a collection of programs designed to operate , control and extend  the processing capabilities  of  the computer system and the other hardware devices connected to the computer system.

The system  software  is also   designed and developed  by the computer manufacturer to  communicate  with  specific  hardware components connected  to  the  computer system.

For example when we connect a new device to the system , we need to first install the device driver to operate the device such as  camera , printer , scanner and other such devices .  

System Utility Software
Types Of System Software

Both  application programs and the operating system needs a special software called device driver to  communicate and to drive the various hardware components connected to the computer system .

The device driver is a  system  software  which functions  as an interface between the computer  hardware  and  the operating system .

The  system software programs  are  generally  written  in  a low level programming  language   such  as assembly language . 

Application Software

The application software provides an interface to the computer user to perform a specific job on the computer system . For example , writing document , making presentation or managing accounts .

Application software are installed on the system to provide specific functionality to the system . The  Application software is  designed  and developed  to satisfy a specific  need  of the computer user  .

For  example MS Office , accounting  software ( Tally )  ,  engineering  drawing  software (  AutoCAD ) are some of commonly used application software.

Application Software
Computer Architecture

Application  software  can  be  single  program application  or  a  group  of   programs  bundled together such  as  MS  Office. Each of these  program in a bundle has been  designed  to provide specific functionality  to the  user  .

Evolution Of Computers

The  Computers  are today integral part  of the human world  and human world today  critically depends  upon the  computing  power of  today’s modern computers . 

The applications of computers are indispensible part of every industry we can possibly think of .

The Computer Science and technology  has  also evolved  over period of last few decades both in the hardware technology and also in the software domain. 

However , The history of computer science began  , long before our today’s modern discipline of computer science.

In the past seventy years , the computers have evolved from room-size mega boxes to the desktops computers. And now, computers are  in  our pockets  with far  more computing power  and mobility.

Evolution Of Computer

But the modern computing-machine era began with Alan Turing’s conception of the Turing Machine, and the  invention of the transistor by three Bell Labs scientists.

The invention of transistor was a major breakthrough in the field of digital electronics . The transistor is tiny electronic component that used as a micro-switch in digital electronics .

The transistors soon replaced the bulky voles valves used in the second generation of computers. The transistors are fundamental building block of all modern processor chips . 

Turing Machine

The turing machine is an important mathematical computation model in the theory of computing . Although this model was first proposed and invented by Alan Turing in year 1936 .

The turing machine model is still considered to be a standard of computational model to verify a particular problem can be solved using a computer system .

Turing machine is still relevant despite the passage of time and the advancements in the various fields of computer science . Despite the simplicity of the model , the turing machine can simulate both simple and a very complex algorithm.

Computer Science Evolution , Introduction to computer system

Evolution Of Computers

Computer Architecture

The CPU is the brain of the computer system which performs all the mathematical calculations and logical operations . The CPU consist of millions of tiny components called the transistor. 

The transistor functions as a micro switch that can be simulate the two binary states ( 0 and 1 ) .

Why Computer Use Binary Number System , Computer System

The transistors are made-up of semiconductor material silicon. The transistor can easily functions as micro-switch to represent the two states ( ON – 1 And OFF – 0 ) in binary . The transistor  is a fundamental building block  for all digital electronic devices  including computers .

The  invention  of tiny electronic component transistor  was a major technological leap forward that has  made the modern-style computing possible today .

The invention of transistor was an important milestone in field of digital electronics   which rewarded  the three Bell lab scientists  with  the 1956 Nobel Prize in Physics . The Microprocessor consist of millions of these transistors.

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