This is mainly for the new members. It is meant to explain some on the member status you see under each members name.
You will see : New member, Expert Contributor/Expert Member, Expert Member, Administrator/Expert Member, Senior Member and maybe more.
All this indicates is how many posts a person has. (except Administrator...he owns the site
).
I'll let Larry explain it further. As well as how the karma works.
Long and short of it is, when you see these status ranks, you'll also have to take into account the quality of the members posts.