First of all, SNS provided great amount of information and news. We can get important global news through SNS. For instance, we can “follow” twitter account of BBC or TIMES for free. I even know the death of Steve Jobs by seeing twitter on the train in the morning. SNS give us not only global or national important news, but also personal information. When big earthquake occurred in 11th March in japan, although it was difficult to contact with family or friends because phone line was stuffed with so many calling, people were able to if their family members or friends are safe by using SNS. SNS is very useful tool to inform people even in emergency.
Second, SNS is necessary to make or keep relationship. Nowadays, people’s life is busy, so it is hard to keep often meeting every friend. Family members are also difficult to meet since many young people go to big city to get job and left their parents behind, because most cities are center of economics of each nation. Not only to keep relationship, SNS let people make more relationship and opportunities. By using “searching” system, people can easily find people who go to same school or have same interests. Since SNS is used by any people who can access the internet without border of nation, you can have global connection. It will help your broader understanding