The command clear clears the screen. An alternative way to clear the terminal screen is through a shortcut: Control-L.
Control-L gives you a bonus: if you are in the middle of typing a long command, hitting Control-L clears the screen without erasing what you already enter on your current command. Whatever you typed in as the current command will appear at the top of the screen.
So, you can finish typing in your command and hit enter to execute it with a pristine screen real estate.