You’ve heard of them, but… Do you really understand them? The name might be a little misleading, because sprites aren’t little images like you might be picturing, a sprite is actually one big image. Have you ever seen the CSS technique where the “on” and “off” states of a button are contained within the same image and are activated by shifting the background-position? Think of CSS Sprites as an extension of that technique. The difference is that instead of just two or three images being combined into one, you can combine an unlimited number of images into one.

Why combine all those images? Isn’t it quicker to have smaller images?

Nope, it’s not. Back in the day, everybody and their brothers were “slicing” images to make pages load faster. All that technique did was fool the eye to make it look like the page was loading faster by loading bits and pieces all over at once. Each one of those images is a separate HTTP-Request, and the more of those, the less efficient your page is.