There is an emphasis in the Stack Exchange philosophy on Community moderation, and in my thought having distinct tags for "moderators" and "moderation" reflects this philosophy.
As noted in the tag summary for moderators, it is for:
Questions about diamond (♦) moderators, their powers, and actions they have taken.
The Help Center describes moderators as "human exception handlers, there to deal with those exceptional conditions that could otherwise disrupt the community."
But the visibility of diamond moderators (elected on a site-basis), however confidential much of their activity, does not diminish the responsibility of users to perform moderation actions commensurate with reputation/privilege levels.
As outlined in Jeff Atwood's A Theory of Moderation (2009), at varying levels of reputation users can:
flag posts (15 pts)
review "first" posts (500 pts)
edit any question or answer (2000 pts)
cast open and close votes (3000 pts)
cast delete and undelete votes on questions (10,000 pts)
"protect" questions (15,000 pts)
cast delete votes on negatively voted answers (20,000 pts)
See the schedule of privileges and reputation levels, esp. the entries annotated as Moderation.