Warlock or Wizard

[gte510i]

No: HPFGUIDX 41798

Okay,
It has been months since I posted last but I have a question that has
been bothering me for quite a while?
What is the difference between a warlock and a wizard?  Ernie
MacMillan said in CoS that Harry could trace is lineage back through
five generations of witches and warlocks.  But not wizards?
Rowling seems to be distinquishing between them, but I have no idea.
Also, what exactly is a hag?


Catherine