A canal boat is a boat designed for use on a canal, a narrow boat is a particular type of canal boat built to fit the narrow locks that can be found on the narrow canals in the UK. A widebeam is another type of canal boat built in the style of a narrowboat but wider than the narrow locks.
Although too wide for the narrow canals these widebeams can be used on the broad canals such as the Leeds & Liverpool, Kennet & Avon and Grand Union Canals. For canal boat holidays in the United Kingdom narrowboats are the most common.