30 + years in IT, and I remember many tech’s and computer folks talking about DB-9 serial connectors. I needed a d connector for a joystick to Arduino project, and found to my amazement we’ve been calling them wrong for years (ok, so I kinda remember the correct terminology, but the wrong ones were so commonly used). The Joystick uses a DA-15, the Serial a DE-9, and the printer used a DB-25. D stood for the shape of the shell, the second letter (A, B, C, or D) stood for the size, and the numeral, the number of pins or sockets. VGA is a DE-15HD, or High Density.
Become the Maker you were born to be. Try Arduino Academy for FREE!
I don’t even want to get into the “RJ-45” Connector naming issue, but I guess I will. Ethernet does not use a RJ-45 connector. Ethernet uses a 8P8C connector. a RJ-45 is a mechanically-keyed variation of the 8P8C body with an extra tab that prevents it from mating with other connectors, used in telecom applications.
Hope this sheds some light on issues you never knew were an issue, LOL