Final answer:
The Keypad +/- function in the Edit window when the F8 tool is active and a region is highlighted allows you to zoom in or out on the selected region.
Step-by-step explanation:
In the Edit window, when the F8 (Grabber) tool is active and a region (Clip) is highlighted, the Keypad +/- function is used to zoom in or out on the highlighted region. Pressing the + key on the keypad will zoom in, making the selected region appear larger, while pressing the - key on the keypad will zoom out, making the selected region appear smaller.