Although all brands are different in design, the basic concept is the same. Water comes in at the top, and goes out at the bottom. A pump forces the water to go in a particular direction. When a machine won't drain, there are several things to consider:
Is the drain hose kinked?
Does the lid switch click when closing?
(see video below)
Something in the pump or hoses? Check the hose coming down from the tub for socks, rags, etc.