In Lightroom you can hide the top, bottom, left and right panels so that you have more room to show your images. To hide a panel, click on the triangle at the outside center edge of the panel. Click on it again to show it again. There are shortcuts, of course: Tab hides and shows the left and right panels; Shift-Tab hides and shows all four panels.
Have you ever closed your Lightroom panels, and then been annoyed when they pop open again when you hover over that area with your mouse? If so, you can take control over this situation: right-click (Ctl-click if you have a a one-button mouse) on the panel triangle and choose Manual. Now they will only open and close when you click on the triangle. In “Auto Hide and Show” mode the panel will close when you move the mouse away and open when you hover over the area. In “Auto Hide” mode the panel will close when you move away, and will only reopen when you click on the triangle.