IP Concepts in One Sentence Each

Quoting from Philip Brooks’ Patent Infringement Updates:

• The [patent] exhaustion doctrine is founded on the precept that the authorized transfer of the “essential features” of a patented invention results in exhaustion of system or method claims directed to the invention.
• The contributory infringement statute is based on the precept that a recovery may be obtained for an unpatented component embodying the essential features of a patented system or method.

Source: http://www.infringementupdates.com/2008/03/justice-breyers.html