Final answer:
The command used to display text in a graphics window depends on the programming language and graphics library, with Python's Pygame using font.render and screen.blit, while Java's Swing uses g.drawString.
Step-by-step explanation:
The command to display text in a graphics window varies depending on the programming language and graphics library being used. For example, in Python with the Pygame library, you would use font.render('Hello World!', True, color) followed by screen.blit() to display 'Hello World!' in the graphics window. In Java with the Swing library, you could use g.drawString('Hello World!', x, y) within the paintComponent method of a component.