Block Diagram of Computer

Units of Computer

Basic Units of Computers:-

According to the definition of computer we learn that computer works in an order to complete tasks. It takes Input, Process Data, Shows Output as results and Store data (Temporarily and Permanently).

So We can say that a computer has five basic units in it.

1. Input Unit
2. Memory Unit (Temporary Storage)
3. Processing Unit
4. Output Unit
5. Storage unit (Permanent Storage)

Input Unit:-

This unit is used to give instructions to Computer. It consist of some Keyboard and pointing devices. All the data and Instruction are given to computer through this unit. The devices used to give data and instructions to computer are called input devices.

Memory Unit:-

This unit works as an interpreter between input, processing and output unit. Data and instructions are stored in Memory unit before and after processing. It is a temporary memory because it only store data when computer is power on. All data is lost when power fails or computer is shutdown. RAM (Random Access Memory) is basic part of Memory Unit. Its size is measured in MB (Megabytes) or GB (Gigabytes)

Processing Unit:-

The processing unit of a computer consist of a processor. A processor is called the brain of computer. It does all the works and tasks for computer. It takes data from input unit and process it according to the given instructions. Its speed is measured in MHz (Mega Hertz).

Output Unit:-

The output unit of computer shows the user what is going inside the computer. It also shows the final results. With the help of this unit computer asks any thing required from the user. Errors are also displayed through this unit. Devices attached to this unit are called output devices. Printer, Monitor, Speakers are examples of the output devices.

Storage Unit:-

The storage unit consist of Secondary Storage Devices. It stores the data permanently. Secondary storage device store data magnetically, Electrically or e Optically. Magnetic Tape, Floppy Disk, Zip Disk, Hard disk drive, USB Mass Storage, CD, DVD and Blue Ray Disks are examples of storage devices

Computer joke of today

A teacher asked her students what is the sound of a dog?

Student A: Buff, Buff

Teacher and what of CAT?

Student B: Mew Mew

Teacher and what of a mice?

After a while a student stands up and said CLICK CLICK!

Programming Languages

Programming Languages:-

 Programming languages are the software used to give instructions to a machine. We know that computer is a machine that only understand 0 and 1. all programs are written in programming languages that translate the codes into machine language and tell the computer what to do. There are two types of programming languages.
Low level Programming Language:-
High Level Programming Language:-

Low level Programming Language:-

A low level programming language generally machine code. only a computer (machine) can understand it. It is very difficult for human to understand it

High Level Programming Language:-

A high level programming language is specifically written in a language that is easily understood by human. In order to make it understandable for a machine special software are used these software are as followed.

Assembler:  An assembler is a software that translate the assembly language program into a machine code.

Compiler: A compiler is more powerful then an assembler because it translate a High level language's program into machine code. it also checks for errors in a program. 

Interpreter:An interpreter is a program that translates the each statement of a program into machine code one by one. As it translates only one statement of the program at a time it works very slow.

 

Linker:  High level languages include some built in header files or libraries. These libraries contains some predefined functions, these basic functions which are essential for executing the program. These functions are linked to the libraries by a software called Linker.

Loader: Loader is a program that loads machine codes of a program into the system memory. Most often these programs are part of an operating system. Operating system is responsible for starting a program.

System Utilities (Utilities software)

Utilities (System Utilities):-

System utilities are software that add or provide extra features to computer users, cut, copy, paste, delete, undo, and redo are examples of system utilities. Some utilities help users to analyze, maintain and optimize their computer for example antivirus software. Following are some types of Utilities software.

• Anti-virus utilities
• Archivers
• Backup software
• Clipboard managers
• Cryptographic utilities
• Data compression utilities
• Data synchronization utilities
• File synchronization utilities
• Revision control utilities
• Disk checkers
• Disk cleaners
• Disk compression utilities
• Disk defragmenters
• Disk partitions
• Disk space analyzers
• Disk storage utilities
• File managers
• Hex editors
• Memory testers
• Network utilities
• Registry cleaner
• Screensavers
• System monitors
• System profilers

Application Software

Application Software:-

Application Software are designed to carryout specific tasks on a computer These software are designed to used by users. These software consist of stand alone software as well as bundle (package) software. These software are further categorized in following types

• Word Processing Software
• Database Software
• Spreadsheet Software
• Presentation Software
• Enterprise Software
• Information Worker Software
• Educational Software
• Simulation Software
• Content Access Software
• Application Suites

System Software

System Software:-

 System software are software that we need to operate a computer. These software directly control the computer hardware. These software also help different hardware components to communicate with each other as well as with system. Following are the types of system software.

1. Operating System (Windows, Mac, Linux, Unix, etc.)
2. Device Driver Software

Some time device driver software are also considered as a part of operating System but I will define both separately.

Operating System:-

It is most likely a set of software, tools, utilities and some application software used to operate a computer system. The Operating system provides an environment in which a user can easily operates (controls) a computer. Windows XP, Windows Vista, Windows 7, Windows 8, Linux, Unix, Mac OS are examples of Operating systems.

Device Drivers Software:-

The Device Driver software contains information about any device attached to a computer. It helps the computer (operating system) to recognize the devices attached with computer. Some devices automatically install their software when attached to computer. These are called plug and play devices. Other devices do need to install their drivers through control panel in computer.