What are the forms for igneous?

Igneous rocks can be classified into two main forms: intrusive (or plutonic) and extrusive (or volcanic). Intrusive igneous rocks, such as granite, form from the slow cooling of magma beneath the Earth's surface, resulting in large crystals. In contrast, extrusive igneous rocks, like basalt, form from the rapid cooling of lava at or near the surface, leading to smaller crystals. These two forms reflect the different environments and cooling rates involved in their formation.