What is the advantage of including parity bits in ASCII characters?

A parity bit is an extra bit added to a string of data bits, such as an ASCII character, to ensure that the total number of 1-bits in the string is always even or always odd. When the receiver checks this parity bit, it can easily determine if a single-bit error occurred during transmission. While parity bits are excellent for basic error detection, they do not provide enough information to correct the error on their own. Furthermore, because adding parity bits introduces overhead to the data stream, they actually slightly decrease the effective transmission rate rather than making it faster.