A feedback circuit is a system that uses the output of a process to influence its own operation. This can help stabilize or enhance the performance of electronic devices. For example, in an audio amplifier, the output sound can be fed back into the system to improve sound quality and reduce distortion. There are two main types of feedback: positive and negative. In positive feedback, the output increases the input, leading to a greater response, while in negative feedback, the output reduces the input, promoting stability. Feedback circuits are essential in various applications, including control systems and signal processing.