When I was downloading materials from Coursera for archiving, I think I found the boundary between the 'Internet' and the 'Huliannet'.
China have the most internet users, even more than internet's birthplace. But Chinese people get blocked access to most of the popular websites because their government don't wan't them to. They have crappy replacements like a search engine don't display search result in the first page but advertisements instead. A social network changes it's appearance often but never improve it's user experience.
There is no exact prohibition rules announced, they just block sites with no reason. The superficial conjectured reason is that the governments don't want their citizens to see some contents that reveal their shady-history. Another reason is that they intend to control the whole internet in their land, like radio and publications. But that is not possible for a distributed architecture when users can just get an IP address from ISP and setup a server in their living room.
Government reply is to issue a law that prohibit the existence of websites based on home network. Almost all of ISP blocked port 80 in order to response to the law. They also issued a law, compulsory requesting data centre users report their usage of their servers that provide internet services, or they have to shut down their website by themselves or by force.
But that does not extinguish the demand of setup personal websites with low cost and without censorship. Lots of website legal or illegal, use virtual private servers overseas. The government cannot just rush into their data centre and unplug the server to shutdown them down.
That's why the Great Firewall launched. This secret weapon have no official name, but almost every internet users in China know it's existence. It have been developed form a simple firewall that can only block by IP address, to a internet behaviour management system that can block websites by keywords. Now, it can detect encrypted network traffic and interrupt the connection. The firewall also turned into a weapon to attack overseas websites by hijacking Chinese user traffic to their target, it was known as the GitHub attack.
According to my observation, foreign websites are slow like hell in China even they have not been blocked yet. For a 100 Mbps network, there is only 10Kbps when downloading in daytime and 100Kbps at night (CST).The firewall might slowed down the foreign circuit. As a result, I cannot watch twitch in medium quality. That's annoying.