All the data movements within a computer via buses. A bus is a group of electrical conductors and mostly wires.. A bus can be copper traces on a circuit board or wires in a cable.
Usually a bus is a multiples of eight (8,16,32,64.....). In the earlier computers,engineers used a set of 8 wires for constructing buses, because of this it allows transmission of eight bits,or one byte on the same time.The number of parallel wires in a bus is called the bus width.Wider the bus ,more bits can be send simultaneously resulting in faster data transmission. Its mean 8 bits bus can send only 8 bits of a data at a time and 32 bits bus can carry 32 bits data at a time.
Type Of Communication :-
Parallel Communication-
This is a method of sending several data signals simultaneously over several parallel channels.This enables the data to travel faster.
Serial Communication -
In many computer data carry in serial order ,one after the an other in a sequence. This means only a single bit can be send at any given time.This type of communication is called serial communication.This communication provides slow data communication.
Best Example :-
In the cinema hall has a single ticket booking counter,then it is a serial communication and if the cinema has multiple ticket booking counters then it is a parallel communication.