Best film reboot

I just don't get the finer differences between remake, reboot, re-imagining and retcon.

 

A remake is reproducing essentially the same original story with only superficial changes to accommodate cast changes, new film technology and present-day scenery.

"Superman Returns" is a weird hybrid of remake, retcon and sequel, but essentially it's supposed to be the same people from Superman I and II.

A reboot is a restart of a previously existing franchise with some significant but not fundamental changes.

Star Trek 2009 and the Abramsverse is a reboot of the original teevee series, using the alternate timeline BS to allow linkage to the "prime" continuity.

Reimagining is a restart of a previously existing franchise with fundamental changes to the main character: basic origin, secret identity, powers, etc etc.

The "Hawaii Five-0" teevee show is a reimagining. McGarrett and Dan-O are given completely new backstories, and the unit itself is given a new backstory never mentioned in the original series.

Retcon is returning to an existing franchise and declaring some previous events and storylines inoperative and thus negated.

 

So... we are living in retcon times?