The "anointed one" in the Bible refers to the
Messiah (Hebrew) or
Christ (Greek), both of which literally mean "anointed one."
In the Old Testament, kings, priests, and prophets were sometimes anointed with oil as a symbol of their consecration and empowerment for their roles. The idea of a future, ideal "anointed one" developed over time, especially within Jewish eschatology. This figure was expected to be a king from the line of David who would restore Israel and usher in an era of peace and justice.
Christians believe that Jesus of Nazareth is the Messiah, the fulfillment of these Old Testament prophecies. They believe he was anointed by God with the Holy Spirit (rather than literal oil) to fulfill his roles as prophet, priest, and king.
So, in summary:
* Jewish tradition: A future king from the line of David, expected to restore Israel.
* Christian tradition: Jesus of Nazareth, believed to be the Messiah foretold in the Old Testament.