The camera probably presents itself as a mass storage device in english just another hard drive. With older operating systems like XP it often wouldn't have a driver built in hense the need for a disk to give it a driver program so it could talk to it,(XP is about 13/14 years old now).
More modern operatating systems support more hardware by default and most things that can plugin tend to identify themselves as a simple device (even though they are quite complex) and use established protocols (standard methods of communicating) to enable the two devices to talk to each other.
So when you plugin the camera it becomes a harddrive to the laptop probably E: or F: on windows which you can open select photo files to move to the internal harddrive or open straight into a program for editing or displaying or ... the photo's. it is as simple as that. Hope that helps.
With Computers a lot has to be accepted as 'Magic' it just works. Nobody knows every detail of everything which goes on, and nobody has to.
I've more than 30 years experience with computers and I don't know everything. I do know how to find out most everything. If I need the information it is almost always written somewhere and google can find it.
Software is usually written with design patterns, so for example practically every program written (with a gui) has a file menu on the top left of the window. with edit and view next to that and help is always the last menu item. Thats why the kids are so quick.
Imagine a world where cars for example are all different, well they are but there are always three pedals (ok for a manual) clutch brake and accelerator usually there is a wheel to steer with.
Computer software is pretty similar in that most of a program will in general be the same as in any other program. There are a few programs which will use a snazzy new interface but the basic functions are usually still there just not so familiar.
With touchscreens there are a few new methods and some older methods don't work so well. Its hard to place a finger exactly on a small button so they need to be bigger, gestures are used so your finger might drag up and down in a list. There is a bit of learning with these new methods but once you are used to them it becomes easy again.