A portable toilet or mobile toilet is a toilet that may easily be moved around. They may be toilets that can be brought on site, such as a festival or building site, to quickly provide sanitation services. Others may be toilets within mobile vehicles, such as boats or caravans. Some are re-usable and may be moved on to further sites, others are easily installed but become permanent once in place. A major characteristic is that most types do not require any pre-existing services to be provided on-site, such as sewerage disposal, but are completely self contained.