Circle Right means that the dancers will be moving to their right (counter-clockwise as viewed from above).
The dancers continue to circle until the caller tells them to do something else. The caller might say to reverse direction, to circle some fraction (e.g, halfway), or to circle until they get to their Home position.
Two facing couples can also join hands to form a circle of just four dancers. In this case, the caller will almost always specify an amount to turn, and when they are done they back out and form two facing couples again. The amount to turn will be some number of quarters (1/4, 1/2, or 3/4), and the dancers will turn the circle until they have faced that many walls. For example, if four dancers facing head walls do a Circle Left 3/4, they will end facing side walls.