A yacht is a recreational boat. It designates two rather different classes of watercraft: sailing and power yachts. Yachts are differentiated from working ships mainly by their leisure purposes. It was not until the ascendancy of the steamboat and other types of powerboat that sailing vessels in general came to be perceived as luxury items. However, since the level of luxury on larger yachts has seen an increasing trend, the use of the word yacht to mean any sailing vessel has been diminishing and is more and more limited to racing yachts or cruising yachts.

Yacht lengths generally start at 32–35 feet (10–11 m) and go up to hundreds of feet. A mega yacht generally refers to any yacht (sail or power) above 100' or 34 m and a super yacht generally refers to any yacht over 200' or 70 m. This size is small in relation to typical cruise liners and oil tankers.