Forward Error Correction (FEC) is a proactive error-handling technique embedded into transmitted data streams. Rather than waiting for a receiver to detect missing data and request retransmission, FEC adds mathematically derived redundant data packets to the stream at the point of transmission. If some packets are lost in transit, the receiver can use the redundant data to reconstruct the missing packets without any round-trip communication. FEC is used in protocols like SRT to improve stream reliability over unreliable network paths without adding the latency of retransmission.