Some forms take a photo and refuse a PDF, and some people simply want to see a page in a chat without downloading anything. Both need the page as a picture.
Turn a PDF into images →Free every day without an account on some tools. Your file is deleted the moment the job finishes.
Each page is rendered at the resolution you pick — a low setting for something to be looked at on a phone, a high one for something to be printed or read closely. Text stays sharp because the page is drawn again rather than photographed, and a colour page keeps its colour. A many-page PDF comes back as a numbered set, in page order.
JPG for a photograph or a colour page you are sending on; PNG when the page is text or a diagram and you want the edges crisp.
A low setting for something to be looked at on a phone, a high one for something to be printed or read closely.
Yes, one per page, numbered in order.