A chawan, whilst the meaning comes from ‘tea bowl’, can also be used for rice.
Some differences are:
Chawan
Donburi
Smaller, around 10-12cm in diameter
Larger, around 18-22cm in diameter
Intended for tea - but not exclusive
Intended for rice/meals
Shallower
Deeper
Usually don’t have lids included*
More common to have lids
* not common, but there are variants out there which have lids.
But I think the main defining difference is the size. What you put in them I’d say is generally down to preference (it’s quite common for people to use chawans as rice bowls), but it would be a bit strange to use a donburi for tea, since it’s so large.
it’s one of those things in english that has been translated slightly weirdly “donburi bowl” kinda means “bowl bowl” (like shiba inu dog = shiba dog dog and ATM machine = automatic teller machine machine)
Indeed, but you wouldn’t serve a donburi meal in a chawan bowl. Not unless you wanted lots of rice on the table.
I swear, everywhere you go in Japan, all of the official English signage says things like “Sotobori Moat” and “Arakawa River” and “Yashajin Touge Pass”.