Liquid rock especially before it has reached the surface is called magma.

Here's a breakdown:

* Magma: Molten or partially molten rock found beneath the Earth's surface. It is typically found in the Earth's crust and upper mantle.

* Lava: Magma that has erupted onto the Earth's surface.

So, the key difference is where the molten rock is located:

* Magma: Underground

* Lava: Above ground