Computer key shortcuts are keyboard key combinations that the user can press at the same time to perform certain functions. Although Windows and Mac OS X operating systems have different key combinations, similar functions often have similar key shortcuts on both systems. Some key shortcuts work across all applications, and some only work in certain applications.
In an application that displays text, including Web browsers, pressing the A key while holding down CTRL selects all text at once. The user can then press CTRL+C to copy the text, and then CTRL+V in a word processor to paste it. By pressing the Command key instead of CTRL, Mac OS X users can use the exact same key shortcuts.
Some Windows-only key shortcuts are: CTRL+SHIFT+Escape to open the Task Manager, Windows+M to minimize all windows and Windows+R to open the Run dialog. In comparison, Command+Shift+Option+Delete empties the Trash, Option+Mission Control opens the Mission Control preferences, and Command+Shift+T shows or displays a Finder tab on Mac computers.
If using Mozilla Firefox, users can add a bookmark by pressing CTRL+D, CTRL+SHIFT+T to reopen a tab that has been closed recently and CTRL+W to close the currently active tab. Safari users can press Command+M to minimize the window, Command+Option+W to close all tabs except the active one and Command+Shift+L to show the sidebar that includes the bookmarks, the reading list and the shared links pane.