Display or hide the alternate screen in Terminal on Mac
There are two screen buffers for each window in Terminal. The main screen buffer contains a log of all output to the window. The second screen buffer, called the alternate screen, is used for running interactive apps such as the nano text editor and the less terminal pager app.
When you open a new Terminal window, the main screen is displayed. If you run an interactive app, you’re automatically switched to the alternate screen. When you exit the interactive app, the main screen is restored.
For example, if you are using a text editor in the alternate screen and need to refer back to something in the main screen, you can switch between the two screens.
In the Terminal app on your Mac, do any of the following:
Display the alternate screen: Choose View > Show Alternate Screen.
Switch back to the main screen: Choose View > Hide Alternate Screen.