甚麼是caucasians

The answer is yes, even they are not truly "Caucasian"

See here for the explanation:

http://zh.wikipedia.org/zh-hk/%E9%AB%98%E5%8A%A0%E7%B4%A2%E4%BA%BA%E7%A8%AE

English version provides more details.

Also in practice - Caucasian sounds better than White people, which can reduce the tension among diversity.

(For example, I don't think Chinese would like to be called "Yellow" people.)

白種人。 例如英美法國家的白種人。

不是所有白人都叫做 caucasians，白種人又稱歐羅巴人種或高加索人種，是世界上人口最多的人種，佔世界總人口的54%左右。其中以北歐-日爾曼亞種為代表。特徵是膚色淺淡；柔軟波狀的頭髮。眼窩較深；毛髮較為發達；顴骨低；顎骨較平；鼻樑高挺；嘴唇為較薄或適中。

the white people
while man