The word "Rococo", sometimes Rococco, is probably derived from the French word, "rocaille" meaning "rock-work" and was originally used to describe the artifical grottos at Versailles.
Originally rococo work was confined to two dimensions. Quite early on it became influenced by Chinese decorative motifs and themes and then developed into a three dimensional style of quite elegant complexity. Sometimes though the combination of French Rococo and Chinese art developed into fantastic designs that transcended good taste, hence the critical aspects of the description.
English rococo tended to be more restrained for example Chippendale's designs for ribon backed chairs. The most successful exponent of English Rococo was probably Thomas Johnson a gifted carver and furniture designer working in London in the mid 1700s.
There was a brief but unsiccessful revival of the rococo style in England and America during the 1800s