Biot is a small, bowl-shaped lunar crater located in the southern reaches of the Mare Fecunditatis. It is a circular formation with a sharp-edged rim that has not been significantly worn. The inner walls slope down to a small interior floor. The albedo of the wide inner walls is higher than the surrounding lunar mare, giving it a light hue. (wikipedia entry)
A crater is a circular depression likely created by an impact event. On the Moon they are named after deceased scientists, polar explorers, astronauts or cosmonauts.