In digital television, what does a coding rate of 3/4 mean?

In digital communications, the "coding rate" represents the proportion of useful payload data to the total amount of data being transmitted. The total data includes both the payload and the overhead needed for Forward Error Correction (FEC). A coding rate of 3/4 means that out of every 4 bits of data sent, 3 bits are actual payload information and 1 bit is redundant data used specifically for error correction. Because 1 out of the 4 total bits is allocated to FEC, exactly 25% (1/4) of the transmitted data is error-correction overhead. This redundancy allows the receiving station to detect and rebuild missing or corrupted data without needing to request a retransmission.