The window that has the focus on a Microsoft Windows desktop. The active window is the window belonging to the application in which the user is currently working. If several windows are open on a user’s desktop, only one of these windows can be the active window.
A unique color on the active window’s title bar distinguishes it from other windows. If the user enters commands or text using the keyboard, these commands or text will be routed to the program displaying the active window.
To make a window the active window on the desktop, simply click on it using the mouse, or cycle through the windows on the desktop using Alt+Tab.