The IP address "255.255.0.0" is a special type of address known as a subnet mask. It is used in networking to define the range of IP addresses within a particular subnet. This specific subnet mask indicates that the first two octets (255.255) are reserved for network identification, while the last two octets (0.0) can be used for host addresses within that network. In practical terms, a subnet mask like "255.255.0.0" allows for a large number of devices to be connected within the same network. It can support up to 65,534 individual host addresses, making it suitable for larger organizations or networks that require many devices to communicate with each other.