两回事

two quite different things / two unrelated matters

two / both / some / a few / tael, unit of weight equal to 50 grams (modern) or 1⁄16 of a catty 斤[jin1] (old)

to circle / to go back / to turn around / to answer / to return / to revolve / Hui ethnic group (Chinese Muslims) / time / classifier for acts of a play / section or chapter (of a classic book)

to curve / to return / to revolve

variant of 迴|回[hui2]

(old) to report to one's master

matter / thing / item / work / affair / CL:件[jian4],樁|桩[zhuang1],回[hui2]