A longboat is a type of ship's boat that was in use from circa 1500 or before. Though the Royal Navy replaced longboats with launches from 1780, examples can be found in merchant ships after that date
Lines for a 31 ft longboat drawn in 1801. The windlass for working an anchor can be seen drawn in red, abaft the mast.
The longboat from Vasa. Whilst differing from many longboat designs (this example is double ended, when other longboats had a transom stern) the picture shows the windlass amidships for raising an anchor.
Launch is a name given to several different types of boat. The wide range of usage of the name extends from utilitarian craft through to pleasure boats built to a very high standard.
1910 Mathis launch, 15 horsepower universal engine, at Saranac Lake, New York
A police launch operating on the Thames
The steam launch Branksome, at the Windermere Jetty museum
A US Navy launch of the 1940s