From Full Metal Alchemist d20

>== Introduction == Some races have a class level equivalent, called a "Level Adjustment". For instance, a Spirit-bound Armor (Level Adjustment +2) character which is a 1st level Alchemist is roughly as powerful as a Human 3rd level Alchemist. Such a character, though "1st level" in classes, would be much more powerful than its human 1st level companions. In order to make a Spirit-bound Armor character which is equivalent to a human character with levels below its level adjustment, you should use these Racial Classes.

---