An Access Point Name (APN) is a gateway between a mobile network operator’s cellular network and another network, such as the public Internet or a corporate intranet. It is a unique identifier that specifies the network operator to which a mobile device is subscribed, and the type of connection it uses to access the Internet or other networks.

When a mobile device connects to the Internet using a cellular data connection, it needs to connect to the correct APN in order to access the mobile network operator’s data services. The APN acts as a sort of address or routing mechanism, allowing the mobile device to communicate with the correct network and access the Internet or other services.

Each mobile network operator typically has its own set of APNs that are specific to its network and services, and may provide different APNs for different types of connections (such as 3G or 4G LTE). Users may need to configure the APN settings on their mobile devices in order to connect to a particular network operator’s services, or to use custom APNs in order to access specific services or network configurations.