Q. What do you mean by Feedback in amplification?
Feedback : Feedback in its broadest sense means that a certain amount of the output signal is "fed back" into the input. An amplifier - or an element of an amplifying device - is presented with the input signal, and compares it to a "small scale replica" of the output signal.
If there is any difference, the amp corrects this, and ideally ensures that the output is an exact replica of the input, but with a greater amplitude. Feedback may be as a voltage or current, and has a similar effect in either case.