Section 600 Of Article 1. General From California Evidence Code >> Division 5. >> Chapter 3. >> Article 1.

. (a) A presumption is an assumption of fact that the law requires to be made from another fact or group of facts found or otherwise established in the action. A presumption is not evidence.
  (b) An inference is a deduction of fact that may logically and reasonably be drawn from another fact or group of facts found or otherwise established in the action.