Computer and Computer Terms

Computer is an electronic device, which is used for computing and processing the data. The word computer is derived from compute; meaning to calculate, thus it is a machine, which can perform arithmetical operations at a higher speed.

Commonly Used Computer Terms

• Hardware – Physical components e.g. monitor, keyboard, mouse, chips, wires, buses etc.
• Software – Instructions, programs for specific task but they cannot be touched.
• Firmware – Software replaced for hardware and stored in read-only memory as in BIOS.

Units of a computer system

• Input Unit – Data is accepted from the user by it like keyboard, mouse etc.
• Output Unit – Data output and feedback is given by it like printer, monitor etc.
• Storage Unit – Stores data and results of processing like hard disk, optical disk, pen drive, etc.
• Central Processing Unit – Both control unit and arithmetic logical unit are called CPU.

Arithmetic Logical Unit – It is responsible for arithmetic and logical computations.

Control Unit – It maintains order by controlling flow of information.

Representation of information

• Data – It is meaningless and is raw fact as number, character etc. like count of items sold.
• Information – It is meaningful and processed data like which product sells most.
• Binary Number System – It uses two symbols to represent data, i.e. 0 and 1 and its base is 2.

Memory Size (Bit, Byte, KB, MB) –

Unit	Equals		Unit	Equals
1 Bit	0 or 1		1 KB	1024 bytes
1 Nibble	4 bits		1 MB	1024 KB
1 Byte	8 bits		1 GB	1024 MB

ASCII – Computer stores data in a coded form usually the American standard code for information technology (ASCII) is used, which can represent 256 different symbols by using 8 bits.