5 billion people use the internet.

Less than 1% understand it.

This mega thread will get you up to speed—starting today:

1/47 The internet begins in the 1960s as a US government response to the Cold War.

Military leaders are concerned about potential attacks on US communication systems.

And the govt funds the development of a network of computers that can talk to one another—the Arpanet.

2/47 ARPANET

On October 29, 1969, ARPAnet delivers its first message.

The first computer is located in a research lab at UCLA, the second is at Stanford.

By the end of 1969, four computers are connected to the ARPAnet.

3/47 The network grows steadily throughout the 1970s.

4/47 EMAIL

In 1971, computer programmer Ray Tomlinson implements the first email program on the ARPANET system.

He uses the @ sign to separate the username from the name of their machine.

This scheme has been used in email addresses ever since.