Unexpected Terminal behavior on MacBook Air

There are two scenarios: 1) You can right-click on that Terminal Dock Icon and then select the Options menu item to uncheck Keep in Dock, or 2) drag the Terminal application icon a short distance above the Dock and release. That should produce a simulated puff of smoke.

Although some macOS applications are quit by clicking their red traffic light, Terminal is not one of them and it must be formally quit from its application menu or by pressing ⌘Q.

If you did not launch the Terminal app yourself, then some app you are using or allowed to be installed must be utilizing it. If something is causing the Terminal to open and the process completes (you should see an "exit" condition listed open Terminal window), then you can configure the Terminal app to automatically close.

Hi,

It doesn't hurt anything, though if you don't want to see Terminal.app in the Dock, drag the Terminal.app icon to trashcan and release the left side button.