How to Close an Application Window on an iMac Interface

What should you do to close an application window on an iMac interface?

1) Click the red button at the upper left corner of the window
2) Click the green button at the upper left corner of the window
3) Click the blue button at the upper left corner of the window
4) Click the yellow button at the upper left corner of the window
Final answer:

To close an application window on an iMac interface, you should click the red button at the upper left corner of the window.

Explanation: To close an application window on an iMac interface, you should click the red button at the upper left corner of the window. The red button is commonly known as the close button and is used to exit or close the application. Clicking this button will shut down the specific application window while keeping other open windows intact.