title: What in the world is .WORLD on the end of a database identifier?
body: <p>Sometimes I see Oracle databases with names like <code>SOMEDB</code> and other times I see <code>SOMEDB.WORLD</code>.  I can use them interchangeably with no apparent differences.  What does the <code>.WORLD</code> part mean?  Does <code>WORLD</code> have any specific meaning, or is it just an arbitrary string that happens to be used?  I've seen other extensions also.</p>