The Data Link Layer is the second layer in the OSI (Open Systems Interconnection) model, responsible for node-to-node data transfer and error detection. It ensures that data packets are delivered to the correct device on a local network, managing how data is framed and transmitted over physical media. This layer also handles flow control and access to the physical transmission medium, making it crucial for reliable communication. Protocols such as Ethernet and Wi-Fi operate at this layer, facilitating the exchange of information between devices in a networked environment.