The notation "172.16.0.0/12" represents a private IP address range defined by the Internet Engineering Task Force (IETF). This range includes all IP addresses from 172.16.0.0 to 172.31.255.255, allowing for over a million unique addresses. It is commonly used in local area networks (LANs) and is not routable on the public internet. The "/12" indicates the subnet mask, which specifies that the first 12 bits of the address are used for the network part, while the remaining bits are available for host addresses. This structure helps in organizing and managing IP addresses within a network, ensuring efficient communication among devices.