The second layer of the OSI model would be the Data Link Layer which consists of two additional layers - MAC - Media Access Control and Logical Link Layer. Logical Link helps provide flow control, acknowledgment and error notification and the MAC Layer is a fancy way of 'access control'. If you are a 'Star Trek The Next Generation' fan one easy way to describe this layer is the universal translator in the TNG universe. It would essentially translate digital requests into ones their physical counterparts can understand. The same way language would seem to magically pass through this device to the physical data link layer and then, in turn, tell it how to communicate with your brarin and then back out without your needing to know.

The second layer is the Data link layer. It is that layer that operates with switches. this is also the layer that works with MAC addresses. This layer transfers data between adjacent network nodes in a wide area network or between nodes on the same local area network segment.

Difference between a cluster and mirroring?