Blog owner is a user that maintains a blog (a blog creator).
Nickname is a user name (often fictitious) that is displayed to all readers.
A user can define their nickname in the user profile.
Avatar is an image (static or animated) that is associated with an author of
a blog or comment.
User group: each blog can have its own set of users or user groups that are
given different permissions to access messages and comments of the blog.
Friend is a user who is a member of one or more groups created by a blog's
author. A friend has certain permissions to access the blog (e.g. read messages
and/or add comments). The blog author's friends are displayed on the user profile
Friend's page displays a selection of recent messages created by the blog
Blog group is a set of blogs that can have a certain common trait (e.g. blogs
of employees) and can be displayed on a given site.
Message is an article created by a blog owner or visitor.
Message tags are used to classify blog messages by an author-defined subject (e.g.
by theme or purpose).
Comment is the reply that a visitor speaks on the subject proposed by a
Trackback address is an absolute URL to a blog message (e.g.