Both use X-rays. By general radiology I assume you mean conventional radiographs like a chest x-ray. The difference between that and fluoroscopy is that fluoroscopy is a video camera hooked up to a continuous x-ray source. This allows doctors to see blood vessels when contrast is injected or help guid wires and catheters through the body for treatment. A conventional radiograph is a single pulse of radiation.
Tv and stills. Fluoroscopy involves looking at a moving picture of the body. A general x-ray is a still picture. Identical to the difference between a vidoe camera and a snapshot.
Good question. Radiology is a static image acquired using x-ray. Fluoroscopy is a dynamic (in motion) image acquisition using x-ray.