The internet is a giant network of networks. But where did it come from? We break it down below.

https://www.internetsociety.org/internet/history-internet/brief-history-internet/
The 60’s and ARPNET
ARPNET (Advanced Research Projects Agency Network)was created by the US Department of Defense to allow transmitting data from computer to computer. This created the building blocks of the modern internet.
1983 – Birth of TCP/IP
The protocol of TCP/IP set a model for how data could travel between networks. If ARPNET in the 60’s created building blocks for the internet, the adoption of TCP/IP formed the skeleton and infrastructure.
1990 – Going Mainstream
Until the 90’s, the internet was a pretty specialized network, and not very present in the public eye. This changed in 1990 with the creation of the “World Wide Web” by Tim Berners-Lee. This began to take form of the internet we know and use today.
Further reading
https://www.history.com/news/who-invented-the-internet