Yacht
Although there isn’t really a standard definition for a ‘yacht’, as a maritime term it can generally be described as a boat that is used for pleasure or racing. Yachts can be powered both by engine and by wind power - i.e. sailing yachts. Normally a yacht will have a cabin that can be used to sleep in for one or more nights.
Typically speaking, a ‘boat’ becomes a yacht when it exceeds around 40 feet in overall length. Once a yacht reaches approximately (again there is no set definition) 78 feet in length, it falls into the ‘superyacht’ category.