Note: The Command key that is present on a keyboard that is used for iMac and Macbook computers looks like this: 
- COMMAND + C = Copy. Select a portion of a text or a file in your computer and copy it.
- COMMAND + V = Paste. Pastes the text or file that you copied in the area you want to paste it.
- COMMAND + X = Cut. Deletes text (works only if you typed something, not text on the internet or a PDF file) or file.
- COMMAND + A = Select All. Selects the entire text or files in a folder. You can either Cut or Copy the selected parts.
- COMMAND + Z = Undo. Goes back one step if you want to undo a change that you have made in a document.
- COMMAND + P = Print.
- COMMAND + S = Save the document. Very helpful when you are concentrating on a paper on Microsoft Word or Pages.
- COMMAND + T = Opens a new tab in a browser. Works for Chrome, Firefox, and Safari.
- COMMAND + N = Opens a new browser window aside from the browser window that you are using.
- COMMAND + W = Closes a window or tab in browser.
- COMMAND + SHIFT + 3 = Screenshot. Screenshots the entire screen. The image will be saved on the desktop.
- COMMAND + SHIFT + 4 = Screenshot. You can choose which part of the screen you want to take a screenshot of. Once you do, the image will be saved on the desktop.
- COMMAND + SHIFT + Q = Logs out of the macOS. It does not shut down the computer but logs you out if the Mac is being used by multiple computers, like public Mac computers.