surface

Surface may refer to several concepts across disciplines. In everyday language it denotes the outermost boundary of an object or the interface between different media, such as the surface of a table or the surface of a liquid.

In mathematics, a surface is a two-dimensional manifold: a shape whose local neighborhood resembles a plane but that can have curvature and a complex global form. Classical examples include the plane, sphere, and torus; more intricate surfaces arise in differential geometry and topology. Surfaces can be oriented or nonorientable, compact or open, and they may carry additional structures such as curvature and a metric.

In the physical sciences, surface properties influence phenomena such as surface area, which affects reaction rates and heat transfer; surface tension, the cohesive force at a liquid interface; and surface roughness, which governs wettability and adhesion. The study of surfaces also encompasses surface chemistry and processes like adsorption and catalysis at interfaces.

In technology, Surface is a line of Microsoft devices that includes tablets, laptops, and all-in-one PCs designed for touch and pen input. The brand emphasizes portable computing with integrated displays and accessories. In computer graphics, a surface represents the visible face of a 3D object and is central to rendering, shading, texture mapping, and collision detection.