Copyright & Citing Sources: Citation is like a Treasure Map

Citing a resource properly should allow another person to RE-search out the exact same content you mentioned or borrowed. It may be in a website, in print or pdf, but the content should be available and find-able based on the information you cite. 

Style manuals are like a template, a standard that helps keep citations consistent.  This makes it easier to re-search and find original content when the the citation is the only clue to source.  Think of it as a map to a treasure.