Anointed One is the English meaning of two different words.

Messiah comes from a Hebrew word and Christ comes from a Greek word. 

Messiah and Christ both translate to English as Anointed One.

These three words will be used interchangeably on this site.    

The Anointed One was to step out of eternity, come to the earth and bring salvation to people of all nations.

So there would be no mistake and so you would know for sure, many different aspects of his life were prophesied 500-1000 years before he was even born.