The animation, by STI International, shows a M1911 pistol firing a round. Various parts can be hidden such as the slide, frame, magazine etc. so you can easily see how it functions.
It is interesting to compare the multiple manual safety 1911 animation with the Glock animation.
Below is a screenshot of the animation. Click here to view the animation.
Some detailed diagrams showing how the 1911 operates can be found here.