Serial And Parallel Models And Bus Characteristics

• A parallel link transmits several streams of data (perhaps representing particular bits of a stream of bytes) along multiple channels (wires, printed circuit tracks, optical fibers, etc.). 
• A serial link transmits a single stream of data. 
• A number of factors allow serial to be clocked at a greater rate:

1. Clock skew between different channels is not an issue (for unlocked asynchronous links).
2. A serial connection requires fewer interconnecting cables (e.g. wires/fibers) and hence occupies less space. The extra space allows for better isolation of the channel from its surroundings. 
3. Crosstalk is less of an issue, because there are fewer conductors in proximity.

Difference ( Comparison) Between Serial And Parallel Bus Characteristics

The Above Slide compares the Parallel and Serial Bus Characteristics.