Traditional Cache This is the most common cache, usually a tupperware container, ammo box, or bucket filled with goodies and a log book. The general rule of thumb is, "take an item, leave an item, write in the logbook." Some caches are themed, so make sure to read the description before going on a hunt.
		Multi-Cache A multiple cache has 2 or more caches. There are many variations, but most multi-caches have a hint to find the second cache, and the second cache has hints to the third, and so on. An offset cache (where you go to a location and get hints to the actual cache) is considered a multi-cache.
		Virtual Cache A virtual cache is a cache that exists in a form of a location. Depending on the cache "hider," a virtual cache could be to answer a question about a location, an interesting spot, a task, etc. The reward for these caches is the location itself and sharing information about your visit.
		Letterbox Hybrid A letterbox is another form of treasure hunting using clues instead of coordinates. In some cases, however, a letterbox has coordinates, and the owner has made it a letterbox and a geocache. To read more about letterboxing, visit the Letterboxing North America web site.
		Event Cache There have been many cases where geocachers want to meet up at a location to share experiences and make new friends. Event geocaches are locations to meet, and after the meeting these caches are archived.
		Unknown Cache For whatever reason, this cache either does not have a designation or is a surprise to the hunter.