title: what is the difference between utf8 and utf-8?
body: <p>just wondering that what is the difference between <code>utf8</code> and <code>utf-8</code>? or they are just the same? as I have read in an answer here at SO saying use utf8 for PDO as utf-8 generate errors sometimes.</p>
  
  <p><strong>EDITS</strong>
  where would utf-8 be invalid to use? (as answered in another similar question)</p>