What is mobile is movable, but what is movable is not always mobile. Movable means "capable of being moved" and "able to be rearranged": "This statue is heavy but movable." "Easter is a movable date." Mobile means "capable of moving," "responding to impulses and emotions": "Although the player was badly injured, he was still mobile." "She is a lively person with a mobile expression." A heavy sofa may or may not be movable but is never mobile. The antonym of movable is immovable; that of mobile is immobile.
Dictionary of problem words and expressions. Harry Shaw. 1975.