Data within a computer system is transmitted via parallel mode on buses with the width of the. As a result, there is a speedup in parallel transmission bit rate over serial. Less important than the economical advantage of serial transmission.

Definition Of Serial Transmission In Serial Transmission, data is sent bit by bit from one computer to another in bi-direction. Each bit has its clock pulse rate.

Eight bits are transferred at a time having a start and stop bit (usually known as a Parity bit) i.e. 0 and 1 respectively. For transmitting data to a longer distance, data cables are used.

It consists of D-shaped 9 pin cable that connects the data in series. Serial Transmission has two subclasses synchronous and asynchronous. In asynchronous transmission, an extra bit is added to each byte so that the receiver is alert about the arrival of new data.

Usually, 0 is a start bit, and 1 is the stop bit. In synchronous transmission, no extra bit is added rather the data transferred in the form of frames which contains multiple bytes. Definition Of Parallel Transmission In Parallel Transmission, various bits are sent together simultaneously with a single clock pulse. It is a fast way to transmit as it uses many input/output lines for transferring the data. Parallel Transmission uses a 25 pin port having 17 signal lines and 8 ground lines.

The 17 signal lines are further divided as • 4 lines that initiates handshaking, • 5 status lines used to communicate and notify errors and • 8 to transfer data. Key Differences Between Serial And Parallel Transmission • Serial transmission requires a single line to communicate and transfer data whereas, parallel transmission requires multiple lines. • Serial transmission used for long distance communication whereas, the parallel transmission used for shorter distance.

• Error and noise are least in serial as compared to parallel transmission. Since one bit follows another in Serial Transmission whereas, in Parallel Transmission multiple bits are sent together. • Parallel transmission is faster as the data is transmitted using multiples lines whereas, in Serial transmission data flows through a single wire. • Serial Transmission is full duplex as the sender can send as well as receive the data whereas, Parallel Transmission is half duplex since the data is either sent or received. • Serial transmission cables are thinner, longer and economical in comparison with the Parallel Transmission cables. • Serial Transmission is reliable and straightforward whereas, Parallel Transmission is unreliable and complicated. Conclusion Both Serial and Parallel Transmission have their advantages and disadvantages respectively.

Parallel Transmission is used for shorter distance, provides greater speed. On the other hand, Serial Transmission is reliable for transferring data to longer distance. Hence, we conclude that both serial and parallel are individually essential for transferring data.