Parallel Communication vs Serial Communication

Parallel Communication 

When a word of n bits is to be transmitted in parallel, each bit is transmitted on a separate line along with a common ground line with respect to which the status of each line is measured. Thus, a channel comprises of (n+1) lines.
- It is faster.
- Hardware requirement is complex.
- Example : 8255A PPI

Serial Communication

In serial data transfer, each bit of the word is sent in succession, one at a time over a single pair of wire. A parallel to serial converter is used to convert the incoming parallel data to serial form and then the data is sent out with the least significant bit D0 first and most significant D7 coming last of all.
- It is slower.
- Hardware requirement is simple.
- Example : Rs-232C