Roaming refers to the ability of a mobile device to access network services outside its home network. This typically occurs when a user travels to a different country or region and connects to a local carrier's network. Roaming allows users to make calls, send texts, and use data services, but it often comes with additional charges. There are two main types of roaming: national roaming, which occurs within the same country, and international roaming, which happens when traveling abroad. Mobile service providers usually offer different roaming plans to help manage costs, making it easier for users to stay connected while away from home.