If you constantly have more than one program open and you switch back and forth between them throughout the day, you need to be using ALT+TAB.
When you press and hold the “ALT” key, and tap the “TAB” key, a small window will pop showing you all of your open programs, as well as your desktop. Each time you tap “TAB” the selected program will highlight and become visible. When you let go of the “ALT” key the selected program will come to the front and be active. Be sure to hold the “ALT” key so that the selection window remains open, while selecting the program you want.
Use this keyboard shortcut to switch between programs, much faster than using your mouse.