The Navigation Bar contains two groups of buttons.

The top group of buttons (View) let you control what you see in the View Panel. From here you can access and modify plot settings, view history plots, and create or view slide shows / animations :

The lower group of buttons (Setup) let you access dialog panels to set up your model. Starting at the top button (Materials) and working down to the Run button, you can build your model in the most efficient and logical way :

The Problem Setup section explains this procedure in detail:

The Run button at the foot of the bar is used to run (execute) problems :