The video tutorial explains the differences between solid and molten rock, highlighting that molten rock, known as lava when above ground and magma when inside Earth, can reach temperatures of 1200 degrees Celsius. It describes the formation of igneous rocks from cooling lava, particularly basalt, which is abundant in Earth's crust. The texture of rocks, whether fine-grained or coarse-grained, depends on their formation location. The video concludes with how geologists classify igneous rocks based on these characteristics.

How do the textures of rocks formed inside Earth differ from those formed on the surface?

What characteristics do geologists consider when classifying igneous rocks?