A subnet mask is a 32-bit number that is used to divide an IP address into two parts: the network address and the host address. The network address identifies the network to which the host is connected, while the host address identifies the specific host on that network. The subnet mask is used to determine which bits of the IP address belong to the network address and which bits belong to the host address.
Subnet masks are important because they allow multiple networks to be connected to the same physical network. By using different subnet masks, each network can have its own unique network address, even though they are all connected to the same physical network. This allows for more efficient use of IP addresses and makes it easier to manage large networks.
