You can use the "Force Quit" option or the "Activity Monitor" software on a Mac to end all open applications. To use the "Force Quit" feature:- Step 1:- Press "Command + Option + Escape" on your keyboard to open the "Force Quit" window. Step 2:- In the "Force Quit" window, you will see a list of all the apps that are currently running on your Mac. Step 3:- Select an app from the list and click the "Force Quit" button to close an app. Remember that some applications might not respond to the "Force Quit" or "Quit" command; in such cases, you might need to use the "Force Quit" feature or the "Activity Monitor" app. You may free up resources and enhance your Mac's performance by quitting all currently open applications. If you want your Mac to run as quickly as possible, closing any open apps is a good idea.