The real difference isn't "old vs. new" or even resolution — it's where the picture gets turned into digital data, and how many cables that decision costs you at every camera.
Ask most people the difference between an analog camera and an IP camera and the answer is "IP is higher resolution." That used to be reliably true and today often isn't. The actual architectural difference is where digitization happens and what travels down the cable. An analog camera outputs a raw analog video signal that has to be carried, unprocessed, all the way to a recorder before anything digitizes it — and it needs a second cable just to receive power. An IP camera digitizes and compresses the image inside the camera itself, then sends that finished digital video — and receives its power — over a single network cable. Everything else people associate with the two formats, including the resolution gap, is downstream of that one design decision.