To remove some of the clutter of open applications, you can "minimize" a window, taking it off screen but waiting in the background.
To minimize your open window, click the Minimize button, which looks like a dash (-) at the top right side of the application's window. To restore it to the screen, click the application's icon on the Taskbar. Another option is to hold the Alt key down on the keyboard and press Tab until the application icon is selected. When the icon of the application you want to restore is highlighted, release the Alt key.
MINIMIZE ALL APPS (Win 7 and 10)
1. Right click an empty area of the Taskbar.
2. Select Show the Desktop.