In chess in the beginning of the game, we want to bring out our army and get it ready to fight, and we also want to make sure that our king is safe. A lot of teachers use, what is called the ten golden moves, or sometimes it's also know as the bull's head, let me demonstrate.
White brings up a pawn to the center, his goal is then to bring up the other pawn to the center. The two pawns in the center are what is known as a duo, it's a very valuable thing to have, it acts as a shield and you can develop your pieces around and behind it. You can develop one knight here to f3, the other knight goes to c3, this is four golden moves. White brings up a bishop, five golden moves, brings up the other bishop, six golden moves. The king castles gets to safety, seven golden moves, brings up the queen to get out-of-the-way of the rooks, eight golden moves. Nine and ten, the rooks come to the middle of the board and these are the ten golden moves.
It's also known as the bull's head, the two center pawns are supposed to represent the forehead of the bull, the bishops are like it's horns and the rest of the pieces behind the two center pawns are like the body of the bull. And this whole unit is ready to go and start marching down the board and go get the black king.
These are known as the ten golden rules, you might not be able to get your pieces on to these exact squares every time yourself, in fact it's your opponents job to try to stop you from being able to do that. But this is the sort of thing you're trying to do with your pieces in the opening.