Fundamental of Computer
Computer is an electronic device which is capable of receiving information (data) in a particular form and of performing a sequence of operations to produce a result and give output in the form of information. Basically computer has four functions to perform:
- It accepts data input
- Processes data
- Produce output
- Stores the output for further use
The word ‘computer’ has derived from the Latin word ‘computerae’ which means ‘to compute’. Charles Babbage is known as the ‘father of computer’.
Features of computer
The features of computer are:
- Speed: A computer can do billions of instructions per second.
- Reliability: A computer is considered as highly reliable it never do any mistakes.
- Storage: A computer can store a very large amount of data.
Features of computer
On the basis of general performance level there are four types of computers
- Personal Computer: These computers are used for personal use. It comes in very small size, relatively inexpensive and based on the microprocessor technology that enables manufacturers to put an entire CPU on single chip. It is designed for use by one person at a time. A personal computer is also known as Micro Computer.
- Mini Computer: A minicomputer is a type of computer that possesses most of the features and capabilities of a large computer but is smaller in physical size. A minicomputer fills the space between the mainframe and microcomputer. Minicomputers are mainly used as small or midrange servers operating business and scientific applications. Now mini computers are not much used.
- Mainframe: On mainframe computer a large number of people can work at the same time and on same data. It is a large high-speed computer, especially one supporting numerous workstations or peripherals. There are number of terminals in mainframe computers on which many people can work simultaneously.
- Super Computer: These are used for the tasks where massive calculations are needed like engineering, weather forecasting, scientific experiments etc.
On the basis of uses and working system a computer is of three types:
- Digital Computer: A digital computer is a computer which is capable of solving problems by processing information in discrete form. It operates on data, including magnitudes, letters, and symbols, that are expressed in binary code i.e: using only the two digits 0 and 1
- Analog Computer: An analog computer is a computer that uses the continuously changeable physical data such as electrical, mechanical, or hydraulic quantities to perform an operation.
- Hybrid Computer: It combines features of both analog and digital types of computer. They require an anoalog unit and an integral CPU of digital computer. It directs the analog data to the digital computer to perform an operation.
Parts of Computer
There are several components that are needed in computer. Primarily a computer system needs:
- Input unit
- Central Processing Unit
- Memory Unit
- Output Unit
Anything we tell to the computer is known as input. We can give input to the computer using several devices such as keyboard, mouse, scanner, card reader Bar code reader, Joystick etc. An input can be in the form of:
- Data: Data is the row fact given to the computer.
- Program: These are the sets of instructions that tell the computer what to do.
- Commands: These are special codes of keywords that the user inputs to perform a specific task.
Central Processing Unit
This unit process the input given by the user. The CPU performs all the processing work of computer and controls all its parts. The CPU is also known as the brain of computer. There are two parts of CPU:
- Arithmetic Logical Unit (ALU): An arithmetic-logic unit (ALU) is the part of a computer processor (CPU) that carries out arithmetical and logic operations
- Control Unit (CU): The control unit (CU) is a component of a computer's central processing unit (CPU) that directs the operation of the processor. It tells the computer's memory, arithmetic/logic unit and input and output devices how to respond to a program's instructions.
Memory unit is used to store data, this data can be used as input for calculations and it can be sent in form of output. The capacity of memory is measured in the terms of Byte, Kilobytes, Megabytes, and Gigabytes. There are two type of Memory:
- Primary Memory: It holds the data received from input device. It holds the data which is being processed and intermediate results are generated. RAM is an example of primary memory, it is a volatile memory. Its data has been lost if power is switched off.
- Secondary Memory: Secondary memory is known as permanent memory of computer. Data stored in it remains for ever, it doesn’t lost when power is switched off. ROM (Read Only memory) is an example of secondary memory.
An output is data that has been processed into some useful form, the processed data is also known as information. An output can be a
- Hard Copy: This output is printed on paper.
- Soft Copy: This output is displayed on screen or by non-touchable media.
An output can be in the form of
- Text documents: It includes reports, letters etc.
- Graphics: It includes charts, pictures, graphs etc.
- Multimedia: It includes a combination of text graphics, video, audio etc.
It is a set of instruction which directs the computer to process information. Computer software can never be touched. Computer softwares are classified into three types:
- System Software: It coordinates the operation of various hardware component of computer e.g: Dos, Windows 7/Vista/XP/8/10, MAC etc.
- Application Software: it is a st of program for specific use or for a particular application e.g: Ms-Word, Notepad etc.
- Utility Software: Utility software are those which are very often required by many application programs like Anti-virus software.
Any part of a computer that can be touched by us are known as hardware e.g: monitor, CPU, motherboard, printer, scanner etc. The other external computer equipment are called as peripherals like pen drive, joystick etc.