Specifically, the type of igneous rock formed depends on the composition of the lava:

* Extrusive igneous rock: This is formed when lava cools quickly on the Earth's surface.

* Basalt: Forms from low-viscosity lava (flows easily) and is dark-colored.

* Rhyolite: Forms from high-viscosity lava (flows slowly) and is light-colored.

* Andesite: Forms from intermediate viscosity lava and is a medium gray color.

* Intrusive igneous rock: This is formed when magma cools slowly beneath the Earth's surface. The cooling process allows larger crystals to form.

So, while lava flows form igneous rock, the specific type depends on the lava's chemical composition and how quickly it cools.