Derivation in the language: It is a science that searches for the word of words, up from its present place to the farthest place for it. And the derivation in Arabic is three types: a small, which is that between the derivative and the derivative of it is an adult in the meaning and the arrangement of the letters, not in the formula like the harm and the crushing, and the large, which is that there is a propagation between them in the meaning and the letters, not in the man And it is between them It is appointed in the outskirts of the letters