A data link is a method for connecting one location to another in telecommunications, in order to transmit and receive digital information. Data transfer happens over a certain link protocol that allows data to be transferred from the source to the destination. In the OSI model for computer networking, the data link essentially makes up the second layer. It offers procedures and functions for the transfer of data and can also correct errors that occur in the physical layer.
A data link is meant to establish a connection between two devices that need to transfer data between one another. There are three types of data link configurations for establishing connections: simplex, half-duplex and duplex. Simplex is only meant for unidirectional communication. Half-duplex allows bidirectional communication, but not simultaneously. Duplex allows for bidirectional connections that can transmit simultaneously. Data links are largely governed by protocols for the transfer of data.
In simple terms, using a data link, two devices in a network can communicate with each other and transfer data. Establishing a proper data link is essential for a successful telecommunication project implementation.