Just a note, the word 'Caucasian', derived from 'Caucasoid', can have multiple meanings (as can Asian, and African, etc.). For example, some East Indian & Pakistani etc. are considered not only Asian, but technicially Caucasian depending on their ethnic roots. Or another example, North Africans often are actually Caucasoid, in contrast to Sub-Saharan Africans.
Classically, there are 3 main groups (with somewhat controversial names).
Caucasoid
Mongoloid
Negroid