A skylight, skylight (word from the Latin clarus and via[1]​), skylight or skylight is a window or opening located in the ceiling or the top of a wall,[2]​ used to provide light to a room.[3]​.

When located on a roof, the lighting is much greater than that of a window. Despite being generally small and covering a space through which a person can pass with difficulty, it illuminates more than a normal window and ventilates the environment.[4]​ When we talk about a skylight in a Gothic nave, we can use the term cleristory.[1]​.

There are also other systems, such as light tubes – which allow sunlight to be brought into rooms – that are not located right under the ceiling.

An evolution of skylights or skylights are the so-called light pipes (light pipes or sun tunnels in English). The light tube is a tube-shaped natural sunlight collector that transmits it into the interior of a home through a diffuser. It is usually a metal tube, for example, aluminum, and is covered on the inside by glass that acts as a light diffusing element.