You can change the text in the titlebar of a Terminal window to display a variety of information about the window’s configuration.
Choose Terminal > Preferences and click Settings.
Click Window.
Select a setting to modify from the Settings list, located on the left side of the Settings pane.
In the Title section, enter the name you want to appear in the titlebar of the Terminal window.
Select the items you want to appear in the title bar of the Terminal window:
Active process name: The currently running process.
Shell command name: The shell being used in the window.
Settings name: The settings being used to configure the window.
TTY name: The current name of the terminal. The name is equivalent to the result of the “tty” command in UNIX.
Dimensions: The numbers of column and rows in the window.