Feedback is the process by which a system’s outputs are taken as inputs for further action. While the process has been put to practical use for millennia, it was first formally conceptualized by Norbert Wiener (1948) and developed during those Macy Conferences of the 1950s and 60s dedicated to cybernetics.
Feedback helps prevent us from falling over, stops steam engines blowing up, keeps a room at a steady temperature, and is in fact to be found in every single natural and artificial system. It is essential to course correction, governance, and learning.
When represented diagrammatically, the process looks like a circle or a loop. Immediate feedback may then be called a first-order feedback loop, and feedback on the feedback is called a second-order feedback loop, etc.