How Internet Has Invented?

I was curios about how internet has invented. because I'm thinking how big Internet be, like they can access to billion people around the world. I've been curios since i am 10 years old, the internet make me interesting because internet have many application for the people around the world. it have (Skype, Facebook, Twiter, etc).

I have been curious about the Internet because I am confuse how internet can feed billion of application but people can access that application in the same time. I also curios about how the application can save all the information/the document, did they have an building to save the documents? did ?did the Internet use an cable to connect all the information around the world?

my effort to know is by doing research in the internet to found how Internet has been invented, or I found in the article.

Image by Icky Pic