Zippers are a combination of the two oldest inventions which are hooks and wedges.The idea was to latch every hook on to each of the two tracks into a hollow on the opposite track. This latching mechanism, called the slide, is just a collection of wedges. As the slide moves up the zipper, the two teeth strips must enter at specific angle in order for it to lock. As the strips move through the slide, the slide's inclined edges push the teeth toward each other forming a bond between both sides. The strips are offset from each other, so each hollow settles onto a hook in sequence. This has to work properly for the zipper to work, each tooth must be exactly the same size and shape, and they all must be perfectly positioned on the track. Zippers
