Short answers, pulled from the story.
The Internet began on the 29th of October 1969 when the first message was sent from the University of California, Los Angeles to the Stanford Research Institute. The message was the word LOGIN, but the system crashed after the first two letters, leaving the first transmission of the Internet as just the characters LO.
Tim Berners-Lee invented the World Wide Web in 1990 while working at CERN in Switzerland. He wrote the first web browser and server software that year and had built all necessary tools including the HyperText Transfer Protocol and the HyperText Markup Language by Christmas of 1990.
China had 802 million internet users in 2018 when the country's internet regulatory authority announced the milestone. This figure placed China ahead of India which had some 700 million users and the United States which had 275 million users.
A 2018 study by The Shift Project estimated that nearly 4% of global CO2 emissions could be attributed to global data transfer and the necessary infrastructure. Online video streaming alone accounted for 60% of this data transfer and contributed to over 300 million tons of CO2 emission per year.
The TCP/IP protocols were standardized in 1982 by Vint Cerf and Bob Kahn. This standardization allowed different networks to speak a common language and paved the way for the global system we know today.