There are three types of rocks:
Igneous form from the cooling and solidification of magma or lava.
Sedimentary form from pieces of other rocks.
Metamorphic form from the warping of other rocks due to heat and pressure.
Hope this helps!!
Sedimentary rocks are formed because of the pressure of the water. Sedimentary rocks are made of sediment which is bits of dust, sand, dead fish so on and so forth. Therefore Sedimentary only form because of pressure but all rock types use it
