The feedback graphs in Reach Control comprise of position (mm, °), velocity (mm/s, °/s), and current (mA), and are useful to check that your manipulator is behaving as expected.
The Feedback Graph toggle shows/hides the feedback graph along the bottom of the screen (Figure 1), and can be accessed by going to Settings > Display > General (Figure 2).
You can left-click anywhere within the live graphs shown to see the values for each joint.