An IP address (Internet Protocol address) is a unique numerical label assigned to every device connected to a computer network that uses the Internet Protocol for communication. It serves two main functions: identifying the host or network interface and providing the location of the device in the network, similar to how a street address identifies a home. IP addresses are essential for routing data between devices on local networks and across the internet. There are two main types: IPv4, which uses a 32-bit address format, and IPv6, which uses a 128-bit format to accommodate the growing number of devices online.