When using computational mechanics to analyse a physics problem, one or multiple solution fields (e.g. the displacement field of a solid body or the velocity field of a fluid flow) are calculated on a given geometrical domain. In order to use a numerical solution method the geometry has to be discretized (approximation of the continuous geometry by a discrete number of elements/cells).
The discrete representation of the computational domain is called mesh. In this section you have to assign a mesh available in your simulation project to the simulation setup.