Representation of information

Difference between Data and Information

Data	Information
Data themselves are meaningless	Information is meaningful
Data is raw facts like numbers, characters etc. For e.g. Number of items sold today is data, as it is just a number.	Information is processed or manipulated data. For e.g. Which product sells more in a week.

Binary Number System

This number system use only two symbols to represent data, i.e. 0 and 1. Therefore the base of binary number system is 2. In the table given below the decimal numbers are shown with their binary equivalents.

DECIMAL                     BINARY

1. 0                                  0
2.   1                                1
3.    2                              10

Computer being a device easily understands two states i.e. ON (Current is coming) or OFF (Current is not coming). Thus all data and instruction given to a computer is expressed in these two states, known as binary states (Bi meaning two). Hence, data is also measured by computer on the basis of these two states, as we measure distance in Kilometer, time in minutes or seconds, similarly we measure the amount of data in various terms as

Memory Size (Bit, Byte, KB, MB)

BIT

It is the basic unit of information. It means BInary digit (BIT). It represents either a zero (0) or One (1). Computer

works on the principle of “on” or “off” of electronic pulses. 1 represents the passing of the pulse while 0 means

blocking of pulse. Bit is therefore the smallest unit of information.

For example                           0                      1 bit

11                    2 bit

110                     3 bit

NIBBLE

It is a collection of 4 bits

BYTE

It is a collection of 8 bits.

KILOBYTE (KB)

It is equals a thousand (Kilo) bytes, but in Binary form it is represented as 1024 (210). Thus 1KB= 1024 bytes.

MEGABYTE (MB)

It equals thousand Kilo Bytes or 1 MB= 1024 KB or 1 MB = 220 bytes.

GIGABYTE (GB)

It equals thousand Mega Bytes or 1 GB= 1024 MB or 1 GMB = 230 bytes. Thus above information can be summarized as

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

ASCII

In computer system data is stored in a format that cannot be read by human beings. Every computer stores numbers, letters and other special character in a coded form. The most widely used coding system is the American standard code for information technology (ASCII) which can represent 256 different symbols by using 8 bits.