Quit apps on Mac
If you use an app only occasionally, you may want to quit the app when you’re done using it, especially if the app uses significant energy.
To quit an app, choose App Name > Quit App in the menu bar. For example, choose Preview > Quit Preview (or press the keyboard shortcut Command-Q).
Keep in mind that if you click the Close button in the top-left corner of an app’s window, the window closes, but the app remains open (a small dot below the app’s icon in the Dock indicates that the app’s open).
Tip: If an app has windows open when you quit the app, the windows are shown the next time you open the app. To have app windows close and not be shown the next time you open apps, choose Apple menu > System Settings, click Desktop & Dock in the sidebar (you may need to scroll down), go to Windows on the right, then turn on “Close windows when quitting an application.”