* Lava flows are indeed magma that has reached the Earth's surface. When magma erupts from a volcano, it's called lava.

* Volcanic ash is also a product of volcanic eruptions, but it's not directly magma. It's formed when magma is fragmented into tiny particles by the explosive force of the eruption. This fragmentation is caused by the rapid expansion of gases dissolved within the magma.

So, while lava flows are a direct result of magma reaching the surface, volcanic ash is a byproduct of that process, formed from fragmented magma.