When installed on the wings they differ from flaps and spoilers in that they are not intended to modify the lift and are built strongly enough to be deployed at much higher speeds. Ailerons are similar to flaps (and work the same way), but are intended to provide lateral control, rather than to change the lifting characteristics of both wings together, and so operate differentially – when an aileron on one wing increases the lift, the opposite aileron does not, and will often work to decrease lift. When ailerons are designed to lower in conjunction with flaps, they are usually called flaperons, while those that spoil lift (typically placed on the upper surface before the trailing edge) they are called spoilerons.