Here is an example of a early zoetrope. The zoetrope works by tunnelling your vision whilst spinning at speed showing you only a section of the pictures opposite.

Here is a more modern zoetrpe but this time animated by using models rather then images.I feel it is easier to see how it works with this example and the fluidity of the animation far surpasses the one above.

Here is a Disney zoetrope. The method of it portraying animation is the same as the ones above but works in a different way. Rather than your vision being obscured by the actual zoetrope and your vision being directed, a strobe light is activated timed correctly to the rotation of the zoetrpe allowing you to see only segments of its rotation.