Q. Explain about Parity bit?

Parity bit is an error detection bit added to binary data such that it creates total number of 1's in the data either odd or even. For illustration in a seven bit data 0110101 an 8th bit that is a parity bit can be added. If added parity bit is even parity bit then value of this parity bit must be zero as already four 1's exists in 7-bit number. If we are adding an odd parity bit then it would be 1 as we already have four 1 bits in number and on adding 8th bit (that is a parity bit) as 1 we are making total number of 1's in number (that now involves parity bit also) as 5 an odd number.

Likewise in data 0010101       Parity bit for even parity is 1

 Parity bit for odd parity is 0