Hagrid's job

[Hester Griffith]

No: HPFGUIDX 116062



Sorry if this has already been discussed ad nausium, but I'm fairly
new and this just occurred to me.

What is Hagrid's job?  When he first introduces himself to Harry he
states that he is "Keeper of Keys and Grounds at Hogwarts."  What does
this mean?  We know he looks after the grounds and animals, including
the forbidden forest.  We also know he had Harry's Gringotts vault
key(where is it now?  I only assume Dumbledore has it).  What other
keys would he keep?  Wouldn't make more sense for Filch to keep the
keys to Hogwart as he needs access for his caretaking
responsibilities?  Could this be part of why Filch is so nasty?  Or
are there other keys?  Or is it something like a secret keeper and
access to Hogwarts is somehow tied into Hagrid?  Any ideas?

Hester