The combination of words “social network” was born in 1954 and it didn’t have anything common with the Internet.

The person who invented the term was James Barnes: “social network” is a social structure, which includes individuals or groups tied with the same type of activity, common interests, friendship or relationships. So it’s kind of a structure of familiar people, divided by different groups, where every person makes a group of classmates, colleagues or friends around him.

Year after year this scientific concept progressed and got a lot of popularity. The first growth was observed in North America and Eastern Europe. During the society development process we came to age of information and communication, where social network got a lot of popularity.

The first computer social network appeared in 1971 and it was used by military in ARPA Net network.

1988 was a year of IRC (Internet Relay Chat), which gave an opportunity to talk online.

The main event was an Internet appearance, which Tim Berners-Lee made public in 1991.

There was a network named slassmates.com launched in 1995. It was very popular and it became a year of a start of social network development process in the Internet. But still classmates.com is
one of the most popular social networks with almost 50 million users.

In 2004 facebook.com appeared and became very popular around the world right away. The concept of this network was a little different but it made a revolution in the social networks world. It has over 700 million users now.

In 2008 discount service named Groupon appeared which is not a real social network but it uses principles similar to social networks and it invites people to become a part of Groupon community.
Classification
There are a lot of different kinds of social networks now, so let’s have a look at some of them.

By type:

• Clasmates.com (personal communication)
• Linkedln ( business communication)
• YouTube (video)
• Last.fm (audio)
• Flickr( pictures)
• Groupon (shopping)
• Reddit (news)
• Forsquare (geolocation)
• Tumblr (blogging)
• Answers.com (answers and questions)
• Delicious (bookmarks)
• Second Life (virtual worlds)
• Slashdot (thematic)

By availability:

• Facebook (open)
• PlayboyU (private)
• VK (mixed)

By region:

• Hi5 (worldwide)
• Qzone (country)
• InterNations (worldwide)

The very first classification is the most interesting and it has a lot of different contents for different people groups and different aims. So every person has an opportunity to find a niche and to find almost all of the existing subjects. The most popular networks continue growing.

The second classification type shows availability. There are three different types of current classification: open, private and mixed. Every network was created for a purpose and some of the networks were not made public. And just because of their business model these networks are closed. But biggest part of networks is still public and can be used by any person from any social group. That is not liked by a lot of people because of its information publicity. Mixed type social networks usually are not so popular like public networks, because users just don’t like to cross any barriers and they prefer to refrain from such networks.

And the last type shows us the world’s biggest networks which made kind of union between people from different countries regardless of their culture and skin color. Their clones appeared later in different countries and regions. And now we can see a lot of different kind of networks which are tied to a city, region or even corporation and political organization. That means that regardless of who you are and where you are you can always become a part of any type virtual community.