Which specific layer of the OSI model is responsible for logical addressing (like IP addresses) and routing data packets between different networks?

The specific layer of the OSI model responsible for logical addressing and routing data packets between different networks is the Network Layer (Layer 3). This layer is primarily concerned with transporting data packets across various, interconnected networks, not just within a single local network. Logical addressing, such as an Internet Protocol (IP) address, is a unique identifier assigned to each device on a network that allows it to be located and identified globally across these disparate networks. Unlike a physical address (like a MAC address), which is permanently embedded in a network interface card and operates within a local network segment, a logical address can be dynamically assigned and changed, enabling devices to communicate beyond their immediate network boundaries. Routing is the fundamental process at this layer, where specialized devices called routers examine the destination logical (IP) address contained within the header of each data packet. Based on this address and using routing tables, routers determine the most efficient path to forward the packet from its source network to its ultimate destination network, potentially traversing many intermediate networks along the way.