Why are the definitions of lens focal length and magnifying lens focal length different in photography?

I remember that the principle of the camera is actually convex lens imaging. The so-called camera focal length is actually the distance from the object to the convex lens, and it will not work if it exceeds a certain range. At first, the image on the film was reversed, but the developed photo was reversed, and we saw the so-called positive image.

I think so. I've studied it for a long time, and I may remember it wrong, hehe.