Hoping this will cleard your clouds regarding "activity" and "post" (if there is anything left after "boyptc" explanation)

Regarding the Activity points system >
Explanation:
- After your registration you have 14 days cycles in which you can gain up to 14 Activity points.
- Every post generates you 1 Activity point but in 14 days time span you can gain up to 14 Activity points even if you have more than 14 posts.
- On the day 15 the cycle restarts and you can again collect your 14 points.
Interesting thing is if you have posts over the limit from the previous cycle, with the first comment in the new cycle you get the Activity points from the old posts you had in the previous cycle.
Example: I had 28 Activity points and 33 comments before the end of the cycle, with my first post in the new cycle my Activity points went up to 34, the same amount as my posts.
Edit - Posts that you're posting on
Ivory tower or
serious discussion boards are
didn't count as activity