How do you expand the window so it fills the entire screen?

To expand a window so it fills the entire screen, you can typically click the maximize button, which is usually represented by a square icon in the upper-right corner of the window. Alternatively, you can double-click the title bar of the window to achieve the same effect. On some operating systems, you can also use keyboard shortcuts, such as pressing "F11" for full-screen mode or "Windows key + Up Arrow" to maximize the window.