Timelapse photography is, basically, a type of stop-motion animation. Thousands of shots, taken over a long period of time, and then spliced together and sped up—flip-book style—to create the sensation of flowers blooming in seconds or herds of wildebeest running madly around the plains as though the Benny Hill theme were part of their natural migration patterns.
This video—which has some great behind-the-scenes/how-they-did-it clips—serves as an introduction to a whole gallery of timelapse videos*. Once those have inspired you, check out this handy guide to creating your own timelapse photography using a digital camera, some kind of interval timer (either built-in, or rigged), a tripod and a backup external battery supply (motorcycle batteries are suggested!). Plus, get tips for improving your timelapse game from a BBC Earth photographer.
*Not all the videos are viewable outside the UK, but I found several that I could watch in the U.S. Don't give up!