What does 'FCS' represent in an Ethernet frame?

FCS stands for Frame Check Sequence, which is a crucial component of an Ethernet frame. This field is used for error detection and helps ensure data integrity during transmission over a network. The FCS is a 32-bit value that is calculated based on the contents of the frame before transmission. When the frame reaches its destination, the receiving device computes the FCS again and compares it with the FCS value that was sent with the frame. If the values match, it signifies that the frame likely arrived without errors; if they do not match, it indicates that an error occurred during transmission, and the frame may be discarded or a retransmission may be requested.

This concept is vital in network communications as it directly relates to the reliability of data transmission. Understanding how the FCS works is fundamental for network troubleshooting and performance management in Ethernet networks.