What does the number under a user's name mean?

Question

I was browsing through the users section of askubuntu when I noticed something strange:
The number beneath the user's name was not equal to their reputation, although the list was set to be sorted by reputation.
When somebody answers my question, the number beneath their name is the same as their rep, but on the users list, it is not.

Also my number seemed to be negative.

So I have two * questions:

1. What does the number under the users name in the 'users' section mean?

2. What does it mean that my number is negative? is it bad? What can I do to make it better?

   If anyone has answer I would be very thankful, if this question is too stupid or a duplicate, just tell me to delete it,
   thank you.

*(Actually it's 4 questions, the last two ones are not necessary to be answered.)

Answer 1

This is totally normal. The number you're seeing on that page is the amount of rep they have garnered for the period defined in the upper-right:

If you're negative, that means you've lost more rep within this period than you've gained.

It's not entirely bad, it just means that you've been downvoted/downvoted someone else or offered a bounty, and so you lost more rep than you've gained. The easiest way to avoid this is to be active and involved in the community by asking good quality questions and providing good answers and edits.