Social network service
A social network service is a website or service where people talk to, or network with other people. Social Network Service can connect people with same interests (like football, schools, dogs) and friends. Most Social Networks will let you to create profile page with your pictures and information about yourself.
Social Networking was first proposed in early development of internet. 
The most popular websites like Facebook (largest Social Network website helping to connect with friends) and Twitter ("one of the most powerful social media tools on the planet" ) are helping to speed up process of communication. Phone and mail services are slowly becoming less popular thanks to quick and easy way of sharing messages through such a networks.
A social network is used for people to get to know each other more and create new friends/connections. Social networks are also used to share things with other people.
A 2011 survey found that 47% of American adults use a social networking service.
- The Network Nation 2 by S. Roxanne Hiltz and Murray Turoff (Addison-Wesley, 1978, 1993)
- http://www.fuelonline.co/social-media/twitter-management/ Twitter Management and Consulting