http://www.fact-index.com/c/ch/child_pornography.html
http://www4.law.cornell.edu/uscode/18/2256.html
Definitions of child pornography vary widely.
In most countries, "children" are defined to be persons below the age of 14 or 16, and "pornography" is defined to be depiction of actual sexual activity. In these countries nudist magazines with depictions of nude underage persons are widely available.
The United States of America uses a particularly broad definition, which applies to all people appearing to be below the age of 18 and covers all materials aimed at "prurient interests", even if no nudity is involved. In at least one case, nude pictures of small children in bath tubs have been declared to be child pornography.
Definition of pedophilia
http://www.umkc.edu/sites/hsw/issues/pedophil.html
Pedophilia involves reoccurring sexual arousal and desires or fantasies involving sexual impulses toward a pre-adolescent child or children. The pedophile must be above age 16, and the sexual attraction must involve a child of age 13 or younger who is at least 5 years younger than the adult. A pedophile has either acted on these sexual impulses, or the fantasies and / or sexual arousal and impulses disturb the individual. The pedophile is sexually aroused because the child is a child, regardless of the pedophile's sexual orientation, or the child's gender.
http://www.wordiq.com/definition/Paedophilia