Surface Wikipedia open wikipedia design. A surface is the outer part of something. Most surfaces have a width and a length, but no depth. Surfaces are studied in geometry. Examples of Surfaces[change | change source] An apple has a skin on its surface. People live on the Earth's surface. A piece of metal is put in red paint. The metal is taken out of the paint. After, the outside of the piece of metal is red. The parts of the metal that are now red are called the surface of the object. Boats move on the surface of the sea. Notes[change | change source] ↑ Another way to say this is "Most surfaces are two-dimensional. The two dimensions are width and length." This short article about a place or feature can be made longer. You can help Wikipedia by adding to it. This page is based on a Wikipedia article written by contributors (read/edit).Text is available under the CC BY-SA 4.0 license; additional terms may apply. Images, videos and audio are available under their respective licenses.