Congestion control is a field of study within computer networking that focuses on managing the flow of data in a network to prevent congestion, which can occur when there is more data being sent than the network can handle. The goal of congestion control is to optimize the performance of the network by maximizing throughput, minimizing delay, and ensuring fair allocation of resources among users. Techniques used in congestion control include controlling the rate at which data is sent, detecting and responding to congestion in the network, and implementing mechanisms for sharing network resources fairly among users. Overall, congestion control is essential for maintaining the efficiency and reliability of computer networks.