There are four main categories of intellectual property.  The links on the bottom of this page discusses these categories, which include copyrights, trademarks, patents, and trade secrets.  Note that fair use applies to copyright but not necessarily the other three categories.

• Understanding the Different Kinds of Intellectual Property 
  From the publisher of For Dummies® books comes this description of intellectual property and what constitutes each category of IP. Note that For Dummies® itself is a trademark.
• Intellectual Property 
  From the Legal Information Institute of Cornell University Law School, this web site provides a more in depth discussion of intellectual property along with links for information about each category of IP.
• World Trade Organization's Intellectual Property page 
  From the World Trade Organization, which deals with global rules of trade between nations, this page provides a world-wide definition of intellectual property.
• Legal Zoom's Intellectual Property Article Center 
  Providing services and information to consumer about law, Legalzoom's web site contains a bank of articles relating to intellectual property and how to protect your creations including things like photos posted on social media sites.