OpenGL Programming Guide: The Official Guide to Learning OpenGL, Version 4.3, Eighth Edition

Color Buffers

The color buffers are the ones to which you usually draw. They contain the RGB or sRGB color data, and may also contain alpha values for each pixel in the framebuffer. There may be multiple color buffers in a framebuffer. The “main” color buffer of the default framebuffer is special because it’s the one associated with your window on the screen and where you will draw to have your image shown on the screen (assuming you want to display an image there)—all other color buffers are off screen.

The pixels in a color buffer may store a single color per pixel, or may logically divide the pixel into subpixels, which enables an antialiasing technique called multisampling. We discuss multisampling in detail in “Multisampling” on Page 153 ...