Aggression Frequency is calculated as:
(Times Raised + Times Bet) / (Times Raised + Times Bet + Times Called + Times Folded)
Which as a percentage (which is what it shows up as) is the same is % Times Raised + % Times Bet. This number does not depend on VP$IP. A player with an aggression Freq of 60% bets or raises 60% of the time.


Aggression Factor is calculated as:
(% Raise + % Bet) / % Call
A high aggression factor just tells us that player doesn't call very often, not necessarily that they bet and raise a lot.
Aggression Factor has no use without looking at VP$IP.
Two players:
A 60/20/3
B 20/15/3
You can assume player A is actually way more aggressive, since he's active in way more pots post flop (he's a maniac), whereas player B is a standard TAG, who's mostly active when he's got the goods post flop.
Yet they've both got the same Aggression Factor.