Source: https://youtu.be/IyGwvGzrqp8

Serial com is as old as machines with a two wire cable between them. And of course there are a number of serial protocols, which - and that is might come as a surprise to some - are all still in use today.

And when you tinker with hardware, sooner or later you need to dig into that topic. Lucky you … Andrei Gabriel Anghel running the Youtube channel Electronoobs did you a favor and summarizes all the necessary information in his excellent video at once.