The word 'Noise' in communication theory is a barrier to
communication that may weaken or destroy a message that is trying
to be relayed There are a number of ways to classify noise. It can
be subdivided according to type, source, effect, or relation to the
receiver, depending on circumstances. In order to make the
classification more compact, noise sources can be divided into two
main groups: • Noise whose sources are external to the receiver
(External Noise) and • Noise source created within the receiver
itself (Internal Noise). types include: Shot noise; Johnson noise;
Partition noise and White noise