This is a really good reference.
A fun guidebook from Google on things you’ve always wanted to know about browsers & the web (but were afraid to ask).
A helpful place to start is near the Very Beginning: 1974. That was the year that a few smart computer researchers invented something called the Internet Protocol Suite, TCP/IP for short. TCP/IP created a set of rules that allowed computers to “talk” to each other and send information back and forth.