Question

when a body is at motion then which friction froce is acted upon the body and why?

Answer 1

A moving body will experience friction if it is travelling in a medium.
But, as the object is moving with a constant velocity, it could be either moving in a vacuum or a constant force is being applied on the body in the direction of motion such that the net acceleration remains zero.
Now,
The type of friction present when the body is moving with constant velocity depends upon the environment in which the body is travelling, in fact zero friction is experienced by the body when it is moving in vacuum. If there is a medium or a surface then yes we can say it as kinetic friction when two objects are moving relative to each other and rub together (like a sled on the ground). BUT, this is possible only in case of dry friction.