Answer :

The definitions: The rock is a naturally and a solid aggregate of one or more minerals or mineraloids. For example, the Earth's outer solid layer, the lithosphere, is made of rocks.

And now: The mineral is a naturally substance that is solid and inorganic representable by a chemical formula and has an ordered atomic structure.

So, the difference between rocks and minerals is: 

The mineral is different from arock, which can be an aggregate of minerals or non-minerals and does not have a specific chemical composition.