When magma flows, it moves slowly and smoothly over the Earth's surface. This can happen when the magma is relatively cool and viscous, or when it is under a lot of pressure from the Earth's crust.

When magma erupts, it is violently expelled from the Earth's crust. This can happen when the magma is very hot and fluid, or when there is a lot of pressure from the Earth's crust.

Magma eruptions can be very dangerous, and can cause widespread damage. However, they can also be beautiful and awe-inspiring.