Ok, so a vast majority of 3d printers do not connect directly to a PC these days. They have a self contained microcontroller.

The workflow is:

1. You design or download a 3D model you want to to print.
2. Open the 3D model in a slicer software. The slicer takes a 3D model and, using a profile designed for a specific printer's nozzle size and controller, converts the solid volume of the model into G-Code, or machine readable code that is a series of coordinates and move rates. This tells the printer where and how to put plastic.
3. Export the G-code to a .gcode (or other) file. Save that file onto an SD card.
4. Put the SD card in your printer.
5. Select the file on the printer display and away you go.

Now, some printers use a network connection component, eg Bambu printers have a wifi adapter. This let's them download firmware updates and receive print jobs from a computer remotely without needing to move SD cards. This does require the right software, e.g Bambu printers require proprietary Bambu Studio (or it's open source fork OrcaSlicer) that has the networking module to talk to it. This doesn't require special driver setup though.