The watch can have other features and capabilities depending on its intended purpose and be a smartwatch.
Many can connect to external sensors by the wireless ANT+ protocol, and/or to a computer by USB to transfer data and configuration.
A footpod can be used to supplement or replace GPS data, such as providing treadmill speed and distance for the watch to log and share.
Examples of common purposes: GPS watches may also be used to get the correct time.
Examples of these include Seiko Astron, a few G-Shocks, and Citizen Satellite Wave.