Here's a breakdown:

* Volcanic conduit: This is the general term for any channel through which magma travels from a magma chamber to the surface. It can be a single, continuous tube or a more complex network of interconnected channels.

* Magma conduit: This term specifically refers to the tube-shaped structure that is carved by the rising magma.

These conduits can be relatively narrow and shallow, or they can be large and deep, extending several kilometers below the surface. They play a crucial role in volcanic eruptions, allowing magma to reach the surface and erupt as lava flows or explosive eruptions.