What is the purpose of the frame check sequence (FCS) in Ethernet frames?

The frame check sequence (FCS) is a critical component of Ethernet frames used specifically for error detection. It functions by appending a checksum to the data being transmitted, which is calculated based on the contents of the frame. When the frame is received, the receiving device performs the same checksum calculation and compares it to the FCS included in the frame. If they match, it indicates that the frame was likely transmitted without errors. If not, it signals that the frame may have been corrupted during transmission, allowing the device to either request a retransmission or take other corrective actions.

The other options describe functions that are not related to the purpose of FCS. Encrypting data packets refers to securing data, which FCS does not do. Segmenting the network relates to dividing a network into smaller parts for improved performance or security but does not involve error detection. Compressing data aims to reduce its size for faster transmission, which again is not the role of FCS. Therefore, the primary function of the frame check sequence is to detect errors in transmitted frames, ensuring data integrity.