A window is everything you see on a computer’s screen, apart from the menu line on the top, the dock line on the bottom (that can be on a side), or an icon on the right. It has a rectangular shape and mostly a white background. When opening a file (see what it means in “Folders and Files”) appears a window. You can also open a new window by scanning the File menu and choosing “New Window”, “New Document” or just “New”. To have a new window, you can also type the keyboard shortcut (see “Keyboard Shortcuts”) “Command N” ().

Active window. A window is active if the three points, top left, are coloured. If you click the red point, you close the window, which means it disappears. Clicking the orange point minimises, it moves to the dock (see chapter “Dock”). Clicking green point makes the window as big as the screen, and clicking again makes it take its original size. You activate a window by clicking on it, or by choosing its name in the “Window” menu. Another way is to type the keyboard shortcut “Command <” ( ), which activates window after window, in the same application.

A window can be made bigger or smaller, for that you just need to point the mouse cursor on the little square at the right bottom of the window, then you type “Drag” (third key, first row, in the “Keyboard and mouse bis” panel), and you drag that square in the desired position, with the mouse movements ; then by typing once more the “Drag” key, you release the cursor. This operation is named “Drag and Drop”.

You can change a window’s place, by putting the mouse cursor on the bar at the top of the window, and then a “Drag and Drop” operation.

If several windows are open on your screen, you can change the activated one, either by clicking on it, either by choosing its name in the “Window” menu, if you do not change application, either by typing the “Command <” ( ) keyboard shortcut to go to the following window, in the same application, “Shift Command <” () to go to the previous window, in the same application, or “Control F4” (^F4) to go to a window of another application. Clicking on a window of another application changes the application, and you can see that the menu bar has changed. 

To close an activated window, you can either click the red point, top left of the window, either choose “Close” or “Close Window”, in the File or Window menu, or type the “Command W” () keyboard shortcut, which is the fastest way. 

To minimise an activated window, that is put it in the Dock, either you click the orange point, top left of the window, either you double click (see what it means in chapter “Mouse”) the bar, top of the window, either you choose “Minimise” in the Window menu, either you type the “Command M” () keyboard shortcut. Minimising is useful to make place on your screen. To make the window come out again, either you click on it’s icon in the Dock, either you select its icon in the Dock (see how in chapter “Dock”), and then you type Return. 

When a window is longer than your screen, you see a blue line or point on the right, which moves along a rail. The longer the window is, the shorter the line is. Clicking on the rail makes the page either go up, if you click above the line, either go down, if you click under the line. But to do those two operations, it is quicker to type the “Page Up” and “Page Down” keys, that you find on the seventh row, after key “£” of “Keyboard and mouse bis” scanning panel. All the more that those keys go on doing the task, until you stop it by a switch. If you want to go slower, you click one of the two little arrows at the bottom of the rail, but you can also drag the line, along the rail, up or down, with the Mouse and Drag keys. In most applications, if you type “Option Click” () on a certain place of the rail, the middle of the line will be put at that exact place. This is very convenient for very long pages, when you approximately know where you want to go. For some pages, like web pages, you can go slowly up or down, with the “Up Arrow” () or “Down Arrow” t) at the end of the sixth row of that same panel.