Difference between camera optical system and camera

What is the difference between a camera and a camera? If it refers to the camera that used to record in the form of electricity and the camera that used to record in the form of film, I think it is the same if it only refers to the optical system of the lens. But after entering the machine, the subsequent processing of light is different. Cameras show people through the process of "light-electricity-display", while traditional cameras show people light directly. As for the shooting situation (brightness, focus), we should wait until the film is developed.

It used to be different because the camera was simple to realize and the camera could not reach the definition of the camera. However, with the development of technology, there are few traditional film machines, and high-definition movies are all digital, so there is no difference between cameras and camcorders in terms of equipment, not to mention optical systems.