JPEG compresses a photograph into a small file by discarding detail the eye rarely misses, and it has no transparency. PNG keeps every pixel and can carry a transparent background, at the price of a larger file. WebP does both in less space, and is accepted by some marketplaces and not by others.
For a listing, the safe choice is the format that every channel on the seller's list accepts, which is usually JPEG for a photograph on a solid background. A transparent cut-out needs PNG or WebP. The format is a separate question from the colour space: a file can be a valid JPEG and still be saved in a colour mode that a marketplace refuses.