Fleet racing can be either 'one-design' or 'handicap'. One design racing, as at the Olympic Sailing Competition means that boats racing against each other are all the same - the same design, the same sail area etc. Handicap racing means different types of boat can race against each other. Each boat has a handicap or rating so that their finish times can be adjusted or their start time determined so that the slowest boats go first.
Fleet racing can be any length of time with several taking place in a day or as a round the world race such as the Volvo Ocean Race.