Question

Difference between flat fading and selective fading

Answer 1

Thanks for asking this question.
Flat fading : 
In this bandwidth of the signal is smaller than the bandwidth of the channel.
In the flat fading all the components of the frequency  of the signal will have the same  magnitude  of fading with respect to each other.

Selective fading:  Here the bandwidth of the signal is larger than the bandwidth of the channel
Different components of the frequency signal will not experience the same fading.

Answer 2

The difference between two is the following:

Flat fading, or nonselective fading, is that sort of fading in which all recurrence parts of the got signal vacillate in similar extents all the while. Specific fading influences unequally the diverse ghastly parts of a radio signal.

Selective expulsion unequally diverts how regularly groups of any wireless airwaves transmission. Flag fading is really nonselective remover wherever completely consistency parts, for the most part, are relatively changed.