The smallest single color element on an image that is displayed digitally. Not to be confused with pixel which is the smallest single color element of the viewing screen. This term is commonly used when dealing with textures in graphical computer applications.
A texel and pixel may vary in size based on the zoom of the image or texture. For instance if the image/texture is scaled to 200%, four pixels (2x2) will equal one texel.
Textures are represented by arrays of texels, just as computer displays are represented by arrays of pixels.