There is also a very good introductory answer in this subject by Jean-Baptiste Quéru in 2013 [1] where he takes the revers approach of when the page is displaye

There is also a very good introductory answer in this subject by Jean-Baptiste Quéru in 2013 [1] where he takes the revers approach of when the page is displayed, then talks about connection, OS, etc. "simplifying" the answer and going down several levels of abstraction and complexities to give the proper overwhelming sense that this question should impose. It is a very fun text to read and I really recommend it. [1] https://plus.google.com/u/0/+JeanBaptisteQueru/posts/dfydM2Cnepe https://plus.google.com/u/0/+JeanBaptisteQueru/posts/dfydM2C...