a google dork is a google search query with google's powerful search operators to find stuff you wouldn't otherwise with a normal google search. This is very helpful for finding information among other things with the google search engine.

search operators

• "search term"
  searchs google for the exact phrase within quotations.
• filetype:
  restricts the search results to certian a filetype.
• site:
  limits results to a spicific website domain.
• intitle:
  return results with only a certain word(s) in the title
• allintitle:
  like intitle but all of the words specified
• inurl:
  return results with only a certain word(s) in the url
• intext:
  return results with only a certain word(s) in the page content
• allintext:
  like intext but with all the words specified
• allinurl:
  like inurl but with all the words specified
• define:
  define a search with googles built in dictionary search
• cache:
  returns most recent cached version of a webpage.

search expressions

• OR
  return results for X or Y. | can also be used in place of or.
• AND
  return results for X and Y.
• -
  exclude a term or phrase in the search results.
• ()
  group multiple terms or expressions together.
• AROUND(X)
  Find pages containing two words or phrases within X words of each other.

weither to be good or evil is up to you.