What is the significance of subnet masks in networking?

Subnet masks play a crucial role in networking by determining how an IP address is organized into its component parts. Specifically, they indicate which portion of the IP address represents the network and which part identifies the individual host within that network. This division is essential for routing packets of data across the network.

When a device wants to communicate with another device on the same network, it can do so directly using the host part of the address, which is identified by the subnet mask. Conversely, for communication with devices outside of that local network, the network part of the IP address takes precedence, allowing routers to forward packets to the correct destination. Understanding subnet masks is fundamental for network design, efficient routing, and ensuring proper communications between devices in different network segments.