Velcro, also known as hook and loop tape, is a kind of cloth fastener. It is made in two halves - one half is made from lots of tiny loops and feels fluffy. The other half is made from lots of tiny hooks and feels rough. When the two parts are put together, the hooks grip the loops and they stick together. When you undo velcro it makes a ripping sound as the hooks unhook from the loops.
Velcro is often used to keep shoes and bags closed. You can also find velcro on lots of clothing and sometimes to stick things to a wall.
The picture is of velcro but taken very very close, so you can see the hooks and loops.
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A zip is a device that keeps your clothes closed. It is made from two strips of tiny teeth and a slider that meshes the teeth together when you zip it up and unmeshes them when you unzip it.
Zips are found on many, many kinds of clothing. Before zippers were so popular, people used buttons to keep clothes closed.