Authorization in RADIUS, Authorization in freeradius

[George Beitis]

Hi everyone,
I have a general question regarding Authorization in the RADIUS protocol
and how it is implemented in freeradius.  What does the RADIUS protocol
refer to when it talks about Authorization, does it actually refer to
users being probably authorized after being authenticated, using the
protocol?  Are there RADIUS specific attributes that are for
authorization? (not authentication).  There are ways of implementing
authorization into freeradius, but do those simply overwrite the
authentication decision?  DIAMETER provides such authorization messeges
from my understanding but the RADIUS protocol does not talk about any,
is this correct?

thank you very much

regards
George