With this type of stand you can lift the wheels of the motorcycle off the ground, making for easier maintenance, cleaning and tinkering.
In racing, paddock stands are used for a number of reasons, one of them to make fitting the tyre warmers a lot easier. As a bonus, the paddock stands also gives your bike a much sportier look.
Keeping the weight of the bike off the tyres is also better for when the bike is in long-term storage.
There are a number of ways to hook up the paddock stand with the front or rear wheel of the motorcycle, but the most common are the cup-style and the bobbin-style attachments.