Needs Maintenance or Needs Archived

What is the difference and when to use them.  There are so many explanations here that I don't know where to start. 

Needs Maintenance creates an attribute on the cache.  You can filter those out when you run a PQ.  That way caches that may have trouble you can automatically skip.  It lets the owner know there is trouble.  Some reviewers check those regularly.  They don't let me know automatically.  When things are slow I can do a PQ like you and find them and go through them.
A Needs Archived sends a note directly to the reviewer.  I get those and usually look at them instantly.  If you have a number of Needs Maintenance and/or Needs Archived flags, over a reasonable amount of time, you may not get a warning.  Other cachers are policing you and telling you there is a problem, go fix it.  I may leave you a note if it is appropriate, or disable the cache and send you a note.  Time to go look at them.