What is the difference between sailboarding and windsurfing?

Sailboarding and windsurfing: why are there different names for a single the same sport?

In 1964, S. Newman Darby not only invented the sailboard, but he also opened the way to a new wind and water sport – windsurfing.

Sailboarding is the original term used for describing the outdoor activity in which someone stands up on a board that is connected to a mast and sail.