The IP address "239.255.255.255" is a special address used for multicast communication in computer networks. It belongs to the range of IPv4 addresses designated for multicast, which allows a single data stream to be sent to multiple recipients simultaneously. This is useful for applications like streaming video or audio to multiple users. In multicast, data is sent to a group of devices rather than a single device, improving efficiency. The address "239.255.255.255" is often used as a default multicast address, allowing devices on a local network to discover and communicate with each other without needing to know specific addresses.