demon 和 devil 的區別

Only One Devil The word translated Devil is the Greekdiabolos,which means "slanderer." It is always used in the singular when referring to the Devil.

Demons The word translated "demon" comes from the Greek worddaimon,or the diminutive formdaimonion, The root meaning of the Greek worddaimonis "knowing" or "intelligence."

資料來源：

https://www.blueletterbible.org/faq/don_stewart/don_stewart_52.cfm