I believe the names are interchangeable, with merry-go-round or
roundabout  suggesting, but not limited to  the smaller, portable
machines.  Most American carousels turn counterclockwise.  You
will find that the horses and other figures have the "romance"
or carved side on the right side.

Muller, Dentzel, Parker, Carmel, etc., figures that were carved
in America almost all have the detail carving on the right, with
the left or off side only painted, with no detail carving.  The
old European carousels turned clockwise.  Their figures, such as
Savage, have the romance side on the left.  You can check out the
book, "Painted Ponies", for more information.  Another source is
The Carousel News & Trader, http://www.carouseltrader.com

Patty Slayton