Selective retransmission is a feature in the Transmission Control Protocol (TCP) that allows the retransmission of only the necessary packets that have been lost or damaged during transmission. It avoids retransmitting all the packets in a sequence when only a few are missing or corrupted, thereby reducing network congestion and improving the overall efficiency of data transmission. This is achieved by numbering the packets, and when a packet is lost or damaged, the receiving end sends a request for retransmission of only the missing packets, rather than the entire sequence, to the sender. This selective retransmission process helps to minimize data loss and ensures that the receiver gets all the packets in the correct order.
