Blending in OpenGL is commonly known as the technique to implement transparency within objects. Transparency is all about objects (or parts of them) not having a solid color, but having a combination of colors from the object itself and any other object behind it with varying intensity. A colored glass window is a transparent object; the glass has a color of its own, but the resulting color contains the colors of all the objects behind the glass as well. This is also where the name blending comes from, since we blend several pixel colors (from different objects) to a single color. Transparency thus allows us to see through objects.