What is Noise Source in Networking

What is noise source in Networking?

In communication, noise is an error or undesired random disturbance in a useful information signal, introduced before or after the detector. The noise is a sum of unwanted or disturbing energy from natural and sometimes man-made sources.

Noise Examples:

Fluctuations of the electric current in an electrical conductor.

A signal or process with a frequency spectrum that falls off steadily into the higher frequencies etc.

 Noise terminates which access mechanism?

If terminator is not used then signal will reflect back and interfere with other electrical signals due to which noise will create. When noise will create then there will be problem in data. 

Noise is unwanted electrical or electromagnetic energy that degrades the quality of signals and data. If you still not understand this concept then kindly make your query clearer.