Metamorphic rock is rock that has been formed by a large heat source like a volcano. it was some other kind of rock but it melted and hardened in a different way. Sedimentary rocks are made up of small particles like sand, or soil.
sedimentary rocks are made by compaction of other minerals and rocks. You can see little sediments in the rock. Metamorphic rocks are formed most of the time underground when there is magma or heat and pressure. If you look at a metamorphic rock you can see foliation. I am doing this in Science class at school.