"Social Network" is the most concerned Internet term in recent years. Its English abbreviation is SNS. The first S means Social, the second N means Networking, and the third S means Services. The concept of SNS originated from the "six degrees theory" proposed by social network researchers, that is, you can know any stranger through at most six people. SNS moves the interpersonal relationships in real life to the Internet, enabling any person in the world to contact each other.