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.
