What is the primary function of an IP address?

The primary function of an IP address is to uniquely identify a device on a network. Each device connected to a network is assigned a distinct IP address, which serves as its identifier, enabling communication between devices. This unique identification is crucial for routing data accurately from one device to another across the internet or within a local network. By having unique addresses, systems can ensure that information sent from one device reaches the correct destination without confusion.

The other options pertain to different aspects of network functions but do not describe the core purpose of an IP address. Encryption relates to data security, monitoring is about traffic management and analysis, and user authentication involves verifying identities, all of which are essential elements of network management but are not the fundamental role of an IP address.