Almost as old as the computer keyboard is the keyboard shortcut, which can transform several clicks of the mouse into a simple combination of keys. Using these shortcuts can save a lot of time and typing, but they can also make it easy to access tools and functionality that are otherwise buried deep in sub-menus. And yet a surprising number of people either don’t know they exist, or don’t know how to use them. If you’re laboring over a keyboard and not using shortcuts constantly to spare yourself some effort, here are the keyboard shortcuts you need to know.The basicsKeyboard shortcuts are combinations of one or more keys pressed in unison that invoke a command that would otherwise have to be clicked on from a menu (or by typing into a command-line interface). Some keys on your keyboard, like the Function Keys (marked F1, F2, etc at the top of most keyboards) or the Windows Key will invoke commands all by themselves. Others are combined with the Control Key (on Windows machines, sometimes abbreviated as CTRL) or the Command Key (on MacOS machines, sometimes abbreviated as CMD) in various ways to make the magic happen. Other keys typically involved in keyboard shortcuts include the Shift keys, ALT keys, and Option key in MacOS.There are some “universal” shortcuts that are pretty much the same between Windows and MacOS (and even Linux) systems, and some that are unique to each. Plus, you can create your own shortcuts by “mapping” commands to key combinations on your own. While there are hundreds of shortcuts in Windows and MacOS (and more specific to applications), I’ll stick to the most useful pre-mapped shortcuts you can use.Universal shortcutsSome keyboard shortcuts operate in Windows, MacOS, and even Linux environments. They’re also the absolutely essential keyboard shortcuts you should be using to make your life just a little easier:CTRL+Z/CMD+Z: Hitting the Control or Command keys and the “Z” key at the same time invokes Undo, which is possibly the most powerful and useful tool ever invented. Any time you accidentally delete an entire paragraph from a text file or a whole folder from your hard drive, CTRL-Z can usually undo it.CTRL/CMD+A: This will Select everything on your screen.CTRL/CMD+C: This will Copy whatever you have selected on your screen, storing it in your computer’s Clipboard until you need to duplicate it. In Windows, you can also use CTRL+Insert.CTRL/CMD+V: This will Paste whatever’s in your clipboard into a text file or a folder. In Windows, you can also use SHIFT+Insert.CTRL/CMD+X: This shortcut will Cut whatever you’ve selected, deleting it and storing a copy in the Clipboard.CTRL/CMD+W: This will Close whatever is the main focus on your screen at that moment.CTRL/CMD+F: Invokes the Find tool so you can search within a document, web page, or app.CTRL/CMD+P: Will bring up your system’s Print dialog to send your file to the printer.CTRL/CMD+N: This shortcut will create a New window or document, depending on the context. For example, when you’re in Word in Windows, CTRL+N will create a new Word document. If you’re currently in your browser, it will create a new browser window.CTRL/CMD+S: This will Save your current document. In the days before autosave functionality was standard, hitting this shortcut every few minutes was an essential practice. Usually, adding Shift to this (Shift+CTRL/CMD+S) will save a copy under a new file name.CTRL/CMD+R: When you’re focused on a browser window, this shortcut will automatically Refresh the current browser page. Adding in the Shift key (Shift+CTRL/CMD+R) will produce a hard refresh, reloading all data from the source instead of relying on data that’s been cached to speed things up.CTRL/CMD+O: Will trigger the Open dialog for the current application.Windows-specific shortcutsALT+TAB: Pressing the ALT key and the TAB key simultaneously will allow you to Switch between open windows. Hold the ALT key and tap the TAB key until the window you want to access is highlighted, then release the ALT key to select it.ALT+F4: Pressing the ALT and F4 keys together will quit the current application you’re focused on. This is slightly different from CTRL+W, which closes the current document, though sometimes closing the document also closes the application itself, so there’s some confusing overlap here.CTRL+Backspace: This will delete the word to the left of your cursor in a text document or dialog box.WIN+Down Arrow: This will minimize your current window.WIN+D: This combination will minimize all open windows at once, showing you the Desktop.WIN+Left or Right Arrow: This will snap your current window to the left or right of the screen.CTRL+ESC: Hitting the Control key and the Escape key together will bring up the Windows Start Menu. This is mainly useful if your keyboard doesn’t have a dedicated Windows key.F2: Pressing the F2 function key will usually open the Rename dialog for a file.MacOS-specific shortcutsCMD+Q: Like ALT-F4 in Windows, this shortcut combination will close the current application.Option+Delete: Like CTRL+Backspace, this deletes the word to the left of your cursor.CMD+D: This will duplicate files that you’ve selected, essentially combining the Copy and Paste functions into one shortcut.CMD+H: Hide the current app. Option+CMD+H+M will hide all apps, similar to WIN+D in Windows.CMD+M: This will minimize your current window.CMD+Comma: This will usually bring up the application’s preferences menu.There are plenty more than these, but if you can start using these key combinations in your everyday work, you’ll definitely see an improvement in efficiency and a reduction in computer-related rage.