The data link layer, or layer 2, is the second layer of the seven-layer OSI model of computer networking. This layer is the protocol layer that transfers data between nodes on a network segment across the physical layer.
- Delivers frames between nodes on the same level of the network.
- Doesn't cross boundaries of LAN.
- Inter-network routing and global addressing are higher-layer functions.
Source: https://en.wikipedia.org/wiki/Data_link_layer