Buddies welcome new members to the site, essentially. Basically, we have to be friendly and welcoming and whatever, and have to maintain a presence around the different areas of the site.
The other main staff positions are...
HelpLINK Mentor - they give advice through the HelpLINK system
Live Help Operator - like I mentioned, give advice through Live Help
Article Editor - they edit articles written by members of the Articles Team (I'm a member of the Articles Team itself, it's pretty fun

)
And then there's all these higher-up people above us. 
Hope this explained it, the lingo can be confusing at first. 