>Most of the time you want PNG for drawn images. JPEG is only for photos taken with a camera.
You clarified this in your next line, however the above summary, particularly the comment on JPEGs, is wrong.
PNGs are appropriate for areas with common colors, and where clarity is critical - most logos, charts, web comics, etc.
JP(e)G is appropriate for photorealistic images, where there are significant varations, such as, of course, photos, rendered images, photorealistic images, and so on.
I am kind of shocked that anyone is having this discussion right now. This is like circa 1995 that these sorts of discussions were cutting edge (though it was GIF versus JPEG)
You clarified this in your next line, however the above summary, particularly the comment on JPEGs, is wrong.
PNGs are appropriate for areas with common colors, and where clarity is critical - most logos, charts, web comics, etc.
JP(e)G is appropriate for photorealistic images, where there are significant varations, such as, of course, photos, rendered images, photorealistic images, and so on.
I am kind of shocked that anyone is having this discussion right now. This is like circa 1995 that these sorts of discussions were cutting edge (though it was GIF versus JPEG)