Discretize and Mesh
The Discretize and Mesh option will discretize the model boundaries AND generate the mesh, with a single mouse click.
The Discretize and Mesh option is an alternative shortcut for creating the mesh, without having to individually select the Discretize option and then the Mesh option. The results are identical, whether you select Discretize and Mesh, or you select the Discretize option followed by the Mesh option.
For most models, the Discretize and Mesh option will provide an excellent quality mesh. If you do not need to customize the discretization of the model boundaries, then you can simply use this shortcut.
Of course, if the mesh requires customization, you can always Discretize the model boundaries first, use the Custom Discretize option as necessary, and then select the Mesh option.