What are those words above names
These are a "group title". Groups are a way to get people with similar interests together and form communities. Some groups even hold land jointly. You can see which groups are available by searching under Search > Groups.
All group members have titles, which show over your name. There are two types of members: regular members and "officers", who have access to more tools (for instance, they can change the titles, or buy/sell land for the group, eject regular group members, etc).