White people are people with light skin. Most white people are of European origin, but are also found in other places. Sometimes it refers to a larger group: white people among other groups. The term "Caucasian" is often used as a synonym for "white people", but sometimes it means people of the Caucasus Mountains.
Before the modern age, no Europeans thought of themselves as "white". Instead, they defined their race, ancestry, or ethnicity in terms of their nationality (Greek, Roman, etc.). The concept of a unified white race came into use in the 17th century, or later. The strongest proponents of racism in 20th century Europe, Fascist Italy and Nazi Germany, regarded some European peoples such as Slavs as racially different from themselves.