What is Social Networking?
A social networking service is an online service, platform, or site that focuses on building and reflecting of social networks or social relations among people, e.g., who share interests and/or activities. A social network service essentially consists of a representation of each user (often a profile), his/her social links, and a variety of additional services. Most social network services are web based and provide means for users to interact over the internet, such as e-mail and instant messaging. Online community services are sometimes considered as a social network service, though in a broader sense, social network service usually means an individual-centered service whereas online community services are group-centered. Social networking sites allow users to share ideas, activities, events, and interests within their individual networks.

Facebook
Twitter
MySpace
Posterous
Linked.In
Ning

Wikipedia’s list of social networking sites
Top 15 Most Popular Social Networking Sites
2011 Social Networking Websites Review Comparisons
Build your own social networking website

Chatrooms, instant messenger, forums, etc. are excellent tools for meeting people with common interests!

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Isabella
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