What Is a QR Image?
A "QR image" is simply a QR code exported as an image file — PNG, JPG or SVG — rather than left as raw data; once generated, every QR code is an image you can save, print or embed like any other picture.
There's occasionally confusion between "QR image" (the exported file) and scanning a QR code that appears inside a photo — for example, a screenshot containing a QR code, or a photo of a printed code taken from a distance. Most phone camera apps and photo-library scanners can decode a QR code found anywhere in an image, not just when pointed at the physical object live.
For generating one, SVG is the best format for anything that will be resized or printed (infinitely scalable, no quality loss), while PNG or JPG suit direct digital use — social posts, email signatures, slide decks.