Data representation within the computer

Information  is handled in the computer by electrical components such as transistors, integrated circuits, semiconductors and wires, all of which can indicate only two states or conditions . transistors may be conducting or non-conducting ; magnetic materials are either magnetized or non – magnetized in a direction; a pulse or voltage is either present or not present. All information can therefore be represented within the computer by the presence (on) or absence (off) of these various signals. Thus , all data to be stored and processed in computers are transformed or coded as strings of two symbols, one symbol to represent each state. The two symbols normally used are 0 and 1 . these are known as  bits, an abbreviation for BINARY digits . let us now understand some commonly used terms:

1.       BITS : a bit id the smallest element used by a computer. It holds one of the two possible values                  

            the binary value and its meaning.   Value 0 meaning off and value 1 meaning on

A bit which is OFF  is also considered to be FALSE or NOT SET ; a bit which is ON is also considered to be TRUE or SET . since a single bit can only store two values, there could possibly be only 4 unique combinations namely, 00 01 10 11

Bits are therefore, combined together into larger units in order to hold greater range of values.

2.       NIBBLE : a nibble is a group of FOUR bits. This gives a maximum number of 16 possible different values .

3.        BYTES : bytes are a grouping of 8 bit (two nibbles) and are often used to store characters. They can also be used to store numeric values. 

4.       WORD : just like we express information in word , so do computers. A computer “WORD” is a group of bits , the length of which varies from machine to machine , but is normally pre-determined for each machine . the word may be as long as 64 bits or as short as 8 bits.