Final answer:
The data-link layer provides a reliable and efficient communication link between two directly connected devices.
Step-by-step explanation:
The data-link layer is the second layer in the OSI model of computer networking. Its main function is to provide a reliable and efficient communication link between two directly connected devices, such as computers or routers. It is responsible for framing the data into frames, adding necessary control information, and ensuring error-free transmission over the physical layer.
One of the key technologies used at the data-link layer is the Media Access Control (MAC) protocol, which governs how devices access and share a common communication medium, such as Ethernet.
For example, in an Ethernet network, the data-link layer performs tasks such as Ethernet addressing, error detection through checksums, and flow control through methods like backoff timers.