In order to perform any CFD simulation accurately, it is very important to set up the problem correctly. The Physics tab of the user interface is where the physics are defined and the CFD problem is set up. In this lesson we will learn about the Solver group of the Physics tab. We will learn about the General task page, operating conditions, and Reference Values task page. Using these options, we can specify the solver to be used and operating pressure, as well as enabling gravity and specifying reference values for post-processing.