The magma inside the core of the earth heats up and starts moving towards the crust. When the pressure build-up is too high or there is a weak point in the crust, the magma pushes the crust upwards, forming volcanos
When the magma erupts from the volcano, it usually comes out as lava or a more liquidy magma. The magma then flows down the volcano and when it starts to cool, it forms Igneous Rock
Igneous Rock is formed when the magma or lava crystallizes. Magma cools down slower than lava, but it makes larger and more orderly crystals
The igneous rock cools down and forms many little rock fragments called sediments. These little rock pieces are used to make sedimentary rock
Sedimentary rock is formed when sediments are pushed together and molded together by heat and pressure to form sedimentary rock. Sedimentary rock forms layers, the lower you look, the older the rocks are.
Metamorphic rock is formed when many different rocks are smashed together to form a new rock, some example of metamorphic rocks are gneiss, schist, phyllite, and slate. These are all examples of foliated or it consists of thin sheets. The second type of metamorphic rock is non foliated, This includes hornfels, marble, quartzite, and novaculite