The video display on your laptop occupies most of the top half of the clamshell case. Because it's an LCD screen, it looks best within a limited range of horizontal and vertical angles; if you look at the screen from outside that range, the images will be a lot less clear.
Therefore, it's important to move the screen on its hinges for the best viewing angle whenever you use the computer. The hinges that hold the screen to the keyboard section of the computer should hold it in any position, from flat on the table to almost closed.
The brightness and contrast of the screen are the other adjustments that make the display easy to see. On a desktop system, you can often set the levels for the amount of light in the room and forget about them, but if you use your laptop in different locations, you will sometimes move from one place with a lot of background light to another where the lights are dim. Some laptops have a light sensor that automatically adjusts screen brightness to meet the needs of the current location; if yours does not, you should use the computer's manual brightness controls to adjust the screen for the best appearance.
A brighter screen consumes more power, so you can extend the time between battery charges by reducing the brightness. Some laptops include Power Schemes for maximum battery life with reduced brightness. Other power schemes can reduce the brightness after the computer has been idle for a specified period of time.