When you give feedback, it means you offer a helpful response to someone's work or idea.
If you were recording your first album and you asked friends for feedback on which songs to include, you'd be asking them to offer their critical opinions on your music. Feedback is almost always offered or requested with the intention of improving the final product. Another meaning of feedback is a kind of sound distortion from an amplifier or microphone. This sense of electronic feedback has been around since about 1920, while the "critical response" definition didn't come into use until 1955.
n the process in which part of the output of a system is returned to its input in order to regulate its further output
feedback in opposite phase with (decreasing) the input
positive feedback, regeneration
feedback in phase with (augmenting) the input
vicious circle, vicious cycle
one trouble leads to another that aggravates the first