What is difference between a parallel bus and a serial bus?

A Parallel bus has a relatively large number of wires bundled together that enable data to be transferred in parallel. This increases the throughput, or rate of data transfer, between the peripheral and the computer.

A Serial bus can be defined as a transmission path over which the participants transmit their data serially, sequentially in time, and using a common medium.

In the case of serial transmission, only a single communication link for transferring data from any given end to another one. In the case of parallel transmission, we use multiple numbers of parallel links for the simultaneous transmission of all the data bits in the network.