The second layer in The Internet Protocol Stack responsible for moving Frames from one network element to an adjacent network element.
It is implemented in both hardware and software.
Extra features
Framing: almost all link-layer Protocols encapsulate each Datagram in a Frame before transmission onto a Link.Link access control: the MAC Protocol specifies the rules by which a Frame is transmitted onto a Link.Reliable delivery: some protocols guarantee that each Datagram is transmitted across the Link. These are often used on error-prone link, to fix the error locally without forcing an end-to-end re-transmission.Error detection and correction: bit-error can be detected and corrected by a receiving Node. This is often implemented in hardware.