When you login OS X asks you for a password. This is a great security feature, especially if you have a laptop and you are taking it places. If you have a computer at home or in your study and you are the only one that has physical access to your computer you may want to have OS X automatically log you in. Here is how to turn on the automatic login on OS X.
Now next time you restart your machine it will automatically log in and take you to the desktop without you having to type in your password.