# Zones

*Volume mesh zones define different regions within the volume mesh, each with specific physical properties and governing equations.*

In Flow360 zone names are inferred directly from the volume mesh file and cannot be changed.

These zones contain within them [boundaries](./02.boundaries.md), which are used to set up the simulation.

## Types of volume mesh zones

Zones can be assigned one of three types of 3D models:

- [Rotation](../../02.simulation-setup/03.flow-solver/03.physics/03.rotation.md)
- [Solid](../../02.simulation-setup/03.flow-solver/03.physics/02.solid/README.md)
- [Porous medium](../../02.simulation-setup/03.flow-solver/03.physics/06.porous-medium.md)

It is also worth noting that all zones that are not assigned as a solid zone, will be considered a [fluid](../../02.simulation-setup/03.flow-solver/03.physics/01.fluid/README.md) zone.