Depending on the tone of the skin, a Caucasian can still be referred to as a white, but a white can never be referred to as a Caucasian. The races that make up the Caucasian include the northern Africans, Somalians, Arabs, whites, and some individuals in India and Ethiopia. As a matter of fact, the Caucasian race is much more than whites. Basically, the difference between the two races is their skin color. The term "white" is basically used for people from Europe since the 17th century.
On the contrary, the Caucasian race is referred to as the Caucasian, and they can also be called the Caucasoid or Europid. This race comes majorly from South Asia, western Asia, Central Asia, North Africa, Horn of Africa, and Europe. This set of people has referred to also as a biological taxon. For identification, you will identify the whites with their lighter skin color, while the Caucasians are known for reddish-white, pale, dark brown, olive, and even white skin color.