Power kites come in three main forms: parafoils (foils), leading edge inflatables and supported leading edge. There are several different control systems used with these kites which have two to five lines and a bar or handles. By steering the kite with its control lines, different amounts of power can be generated. Most foil kites are made for use on land as they are of the "open-cell" type. This allows air to flow in and out easily. However, kites with "closed-cell" technology do float, so they can be used on water.