This figure illustrates how CAD systems and databases may be incorporated into a software system that uses CGNS. At the top is a box labeled "GUI", and immediately below it is a box labeled "User Control System", representing user-level control of applications. Below this are boxes representing five different types of applications: a CAD system, a grid generator, a solver, a post-processor, and a design/optimizer.
The CAD system uses CAD calls to read from and write into a CAD database. The grid generator uses CAD calls to communicate with the CAD database, and CGNS calls to communicate with a CGNS database. The solver and post-processor both use CGNS calls to communicate with the CGNS database. And the design/optimizer uses CGNS calls to communicate with the CGNS database and CAD calls to communicate with the CAD database.