What Does Subnet Mask Mean?
A subnet mask is a 32-bit number used to differentiate the network component of an IP address by dividing the IP address into a network address and host address. It does so with bit arithmetic whereby a network address is bit multiplied by the subnet mask reveal the underlying subnetwork. Like the IP address, a subnet mask is written using the “dotted-decimal” notation.
Techopedia Explains Subnet Mask
Subnet masks are used to design subnetworks, or subnets, that connect local networks. It determines both the number and size of subnets where the size of a subnet is the number of hosts that can be addressed.
