How do we identify them give example for each classes of rocks?

Rocks are classified into three main types: igneous, sedimentary, and metamorphic. Igneous rocks, like granite, are formed from the solidification of molten magma or lava, and can be identified by their crystalline texture. Sedimentary rocks, such as sandstone, are formed from the accumulation of sediments and often display layered structures or fossils. Metamorphic rocks, like schist, are created when existing rocks undergo transformation due to heat and pressure, characterized by foliation or banding.