Source: http://daily.jstor.org/animated-gifs-a-t...

For those unfamiliar with the term, an animated gif is a “single graphic file that contains a series of images which are displayed sequentially to give the illusion of movement.” Basically, it’s the same thing that initiated the movies. No really, it is.

Think back to your first introductory film course, when you learned about thezoetrope, that Victorian-era device that allowed users to view static pictures of a bird as though it was moving. Gather ’round the kids, spin the wheel, look through the slats, and watch that dove fly, fly away.

Or maybe you recall Eadweard Muybridge’s experiment? You know the one: in which a grizzly-looking photographer rustled up a horse, some trip wires, large cameras, and a racetrack. Then, he ultimately put to rest the age-old question: Is there ever a time when all four feet of a galloping horse are off the ground? (The answer: yes.)

But more importantly, Muybridge put his still images on a disc and then ran them through azoopraxiscope to give them the impression of motion. This little experiment and device, you’ll remember from class, ultimately inspired Thomas Edison and W.K.L. Dickson to create the kinetoscope, also known as our first commercial film exhibition system.