Technically, a “composting toilet” is a toilet in which
composting takes place. Usually, the composting
chamber is located under the toilet. Other toilets
are simply collection devices in which humanure is
deposited, then removed to a separate composting location away from
the toilet area. These toilets are components of “composting toilet
systems,” rather than composting toilets, per se. They can also be
called “compost toilets.”