noun
Refers specifically to ceramic or porcelain bowls, as opposed to wooden bowls (椀). Commonly used for rice bowls, soup bowls, etc.
See also: 椀
この碗は有田焼です。
This bowl is Arita ware.
碗にご飯をよそってください。
Please serve rice into the bowl.
counter
counter for bowls of food or drink
Used to count servings in bowls, e.g., bowls of rice, soup, or noodles.
ラーメンを二碗ください。
Two bowls of ramen, please.
椀 typically refers to wooden bowls, while 碗 is used for ceramic or porcelain bowls.
The kanji 碗 is a phono-semantic compound with 石 (stone) and 宛 (phonetic), originally referring to a stone or ceramic bowl. The reading わん is the on'yomi.