Here are a variety of terms used in social networks:

Archive
An archive is typically used on a blog where visitors can view older blog posts.

Avatars
An avatar is a graphical image of some person. Avatars are used in GaiaOnline, SecondLife, Zwinky, and a variety of other virtual worlds.

Blogs
The word “blog” is derived from “web log,” which simply refers to a website that shows content in chronologically reversed order.  Blogs typically have an RSS feed so that visitors can subscribe to updates (in an RSS reader and sometimes by email). Blogs also typically allow visitors to comment on posts.

Blogroll
A blogroll reveals the blogger’s personal list of favorite bloggers on the web.  The blogger may or may not know these people personally.

Bookmarking
Sometimes people link to a bookmarking site (e.g. del.icio.us) in their online social profile. This is a site that allows members to store links to their favorite websites.

Categories
Content on blogs, forums, or other media within social networks can be categorized (sometimes by tagging).  These categorizations help other members of the site find the content.  Sometimes categories can be created by anyone, but it’s sometimes only reserved to the member to originally added the content.

Chat
Members in social networking sites can often “chat” with each other in chat rooms or through instant messaging.  These discussions are instantaneous and conducted by typing messages back and forth.

Crowdsourcing
Some social network sites have a news section where members can vote news stories up or down. The most popular news items remain on the homepage.  This  is a from of “crowdsourcing” because it uses the wisdom of the masses to decide on content.

Permalink
A permalink is the web address to a particular item on the web.  This is most frequently seen on a blog post – and makes it easy for visitors to link directly to particular content.

Profiles
Profiles are information about users of an online social network.  This is information provided by the user and can contain: pictures, location, short biography, interests/hobbies, education, career information, etc.  The various items listed in a profile often become “tags” and link to other members with the same information.

RSS
RSS refers to Really Simple Syndication.  RSS feeds allow visitors to subscribe to a website’s content and updates. This content may be retrieved through a feed reader (e.g. Google Reader) or sometimes by email (a service offered by Feedburner).

Subscribing
Subscribing refers to the act of adding an RSS feed to a feed reader.  People can also subscribe to online blog content by email.

Tags
Tags are keywords or categories attached to web content.  These words may be used to categorize media, blog posts, or other online content.

Widgets
Widgets are web applications that may be embedded into an online social profile, website, or desktop. These allow users to access certain content without needing to visit another website.