WebFinger is a protocol used to discover information about people and entities on the internet. It allows users to retrieve details like email addresses, social media profiles, and other related data by querying a specific URL associated with a person's identifier, such as their email or username. The protocol works by sending a request to a server that supports WebFinger, which then responds with a JSON document containing the requested information. This makes it easier for applications and services to share and access user data across different platforms, enhancing connectivity and user experience online.