The advantages of the Internet technology have made it possible to emerge a good number of web sites to facilitate social relations among people around the world. These are known as social networking services or social networks. At present, Facebook is the most popular. Google+, Twitter, LinkedIn, etc. are other frequently used social services. Social network services are web-based and hence, provide ways for the users to interact through the Internet. These services make it possible to connect people sharing interests and activities across the borders and thus have made a lot for the users to feel that they really live in a global village. Why are social networks expanding so fast? The answer is simple. Most of the social services are cost-free. You can make use of them free, paying a very little to your Internet service provider. Secondly, you can make your personal profile public before the entire online community. It is like presenting yourself before the entire world. You can also look into other people's profile if you are interested. It is simple and easy. Thirdly, social networks allow users to upload pictures, multimedia contents and modify the profile. Some services like Facebook allow users to update their profiles. Fourthly, networks allow users to post blog entries. User profiles have a section dedicated to comments from friends and other users. Finally, there are privacy protection measures too. A user himself or herself decides over the number of visitors/viewers, and what information should be shared with others. 

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