The focus point of a volcano is not a well-defined term in volcanology. However, if you're referring to the point where magma originates, that would be the magma chamber.

Here's a breakdown of related terms:

* Magma Chamber: This is the underground reservoir of molten rock (magma) that feeds the volcano. It's typically located several kilometers beneath the surface.

* Vent: The opening in the Earth's surface where magma erupts as lava, ash, or gas.

* Crater: The bowl-shaped depression at the top of a volcano, formed by eruptions.

* Summit: The highest point of the volcano.

Let me know if you had something else in mind when asking about the "focus point" of a volcano!