Can you explain what the term 'texture' means in computer graphics?

In graphics programming, a texture is an image or data set applied to the surface of a 3D object to give it detail and realism. Textures can contain colors, patterns, reflections, normals, and other parameters affecting the appearance.

For example, to make a 3D model of a tree more realistic, a bark image texture is applied to its surface. In OpenGL or DirectX, textures are loaded as 2D images and mapped onto models using UV coordinates, which define how the image wraps around the model.