GeoCaching is an outdoor adventure game where players use GPS devices to find hidden containers called geocaches that have been placed at specific locations shared on the internet. Players log their finds online, and the geocache containers usually contain items for trading and a logbook to sign. The goal is to reach the cache location, find the hidden container, and trade or log the find. It involves using GPS coordinates, optional supplies, and exploring both the journey to the location and challenge of finding the cache.