Layer 2 of the OSI model or OSI data link layer has a role to prepare packet of Network layer for transmission and control access to the physical media. Data link layer protocols describe methods for exchanging data frames between devices over a common media.
OSI data link layer prepares a packet for transport across the local media by encapsulating it with a header and trailer to create a frame. From that we can know that a frame contains data, header and trailer. Data is about the packet from network layer, header contains control information about addressing that located at the beginning of the frame and trailer contains control information about error control that located at the end of the frame.
OSI data link layer usually use some protocols such Ethernet, point to point protocols (PPP), high level data link control (hdlc), frame relay and asynchronous transfer mode (ATM) which each protocols performs media access control for specified data link layer logical topology. Logical topology typically used in network are point to point, multi access and ring topology.