When a large IP address is divided into small subnets. Subnet are the small pieces or fragments of the large network. More specifically, subnets are a logical partition of an IP network into multiple, smaller network segments. The Internet Protocol (IP) is the method for sending data from one computer to another over the internet. Each computer, or host, on the internet has at least one IP address as a unique identifier.Each subnet allows its connected devices to communicate with each other.