Time Lapse is a technique in the photography world that uses a whole bunch of photos to create a slow sequence into a fast one or vice versa without the use of video recording. Instead the techniques takes a process of having one image replace another in such a quick way that the motion looks like the sequence has been fast forwarded or slow motioned all in all, this is done by the amount of images in each second. The standard Frame Per Second is 24, whereas with the Time-Lapse you can control how many images you want to see per second depending on the goal of having something slow motioned or sped up to show the beginning to the end in a short matter of time.

Wikipedia. 2014. Time-lapse photography. [online] Available at: http://en.wikipedia.org/wiki/Time-lapse_photography [Accessed: 20 Feb 2014]

The best way to show you how the Time-Lapse works is by using imagery to back up what i said:

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Below is an example of a work that has been published to show how time lapse works.