It is very important in any game of chess to focus on a number of concepts that are proven to be effective. One of these concepts is to control the center of the board. Controlling the center of the board allows you to be very flexible in your game play. When you control the center of the board that you are able to mount a variety of attacks as well as maintain a solid defensive structure. If you have an advantage in the center of the board you have a strong advantage in the game itself and a higher chance of winning.
There are some ideas that a chess player should follow to help maintain domination of the center of the board. First is to not allow your knights to be forced out of the center of the board by your opponent's advancing pawns. If you allow this to happen you are likely to hand over control of the center of the board to your opponent, who then will have the advantage. Understand that if your knights are limited by the edge of the board or by the back rank on the board, they are rendered much less effective than when they are helping to control the middle of the board where they are a viable threat.
Another idea for helping to control the center of the board is to use flanking pawns to capture your opponent's pawns instead of using your own center pawns. As much as possible, try to leave your center pawns in the center and bring out pawns from the sides (C and F files) to capture your opponents advancing pawns. This also allows your knights to remain in the center where they belong. Do your best to control the center of the board and you will drastically improve your odds of winning.