Profile. This is where you tell the world about yourself. Profiles contain basic information, like where you live and how old you are, and personality questions, like who's your favorite actor and what's your favorite book. Social networks dedicated to a special theme like music or movies might ask questions related to that theme.
Friends. Friends are trusted members of the site that are allowed to post comments on your profile or send you private messages. You can also keep tabs on how your friends are using social networking, such as when they post a new picture or update their profile. Friends are the heart and soul of social networking. It should be noted that not all social networks refer to them as 'friends' -- LinkedIn refers to them as 'connections -- but all social networks have a way to designate members as trusted.
Groups. Most social networks use groups to help you find people with similar interests or engage in discussions on certain topics. A group can be anything from "Johnson High Class of '98" to "People Who Like Books" to "Doors Fans". They are both a way to connect with like-minded people and a way to identify your interests. Sometimes, groups are called by other names, such as the 'networks' on Facebook.
Discussions. A primary focus of groups is to create interaction between users in the form of discussions. Most social networking websites support discussion boards for the groups, and many also allow members of the group to post pictures, music, video clips, and other tidbits related to the group.
Blogs. Another feature of some social networks is the ability to create your own blog entries. While not as feature-rich as blog hosts like Wordpress or Blogger, blogging through a social network is perfect for keeping people informed on what you are up to.
Widgets. A popular way of letting your personality shine through is by gracing your social networking profile with web widgets. Many social networks allow a variety of widgets, and you can usually find interesting widgets located on widget gallerie