The word Christos is found at least 569 times in the Greek language version of the New Testament. It is almost always translated as "Christ," in reference to Jesus, such as in Matthew 1:1, Mark 1:1, Luke 2:11 and so on.
Christos means, based on Strong's Concordance (#G5547), the Messiah or the anointed One. This title can only refer to Jesus, the Messiah sent by God to save man from his sins.
An allusion to this title, as used for Jesus, is made when a person is anointed with oil in order to be made king. Samuel did this with David when he was first chosen to be king while the prior king, Saul, was very much still alive (1Samuel 16:12 - 13). Hence, being the 'Anointed One' meant, among other things, that the Lord was to be a king (John 18:37, Luke 1:31 - 33).
Not of this world
We find, however, in the Gospel of John (John 18:36) that Jesus explained that His kingdom was not of this world. This meant that he would not make Himself king by human means, such as when He withdrew from a crowd that wanted to make Him their ruler by their force (John 16:15).
Jesus will be made king by divine fiat when He returns during his Second Coming (Revelation 19:14 - 16). Being the Messiah or Christ indicates that the Lord will have royal prerogatives and be able to rule the earth (Daniel 7:13 - 14, 2:44). At that time, all human governments will be abolished.
After Christos returns to earth as God promised (Acts 1:11) the world will experience having a true direct theocracy (not merely humans ruling in God's name, such as in Iran's "Islamic Republic"). He was anointed by the Holy Spirit, it should be noted, not literal oil (see Acts 10:38 and Luke 4:18).
Another allusion to this title belonging to Jesus comes from the high priests being anointed in the Old Testament when being ordained (Leviticus 8:2, 10, 12). He was also to be the high priest, after the order of Melchizedek, for Christians after His death and resurrection (Hebrews 5:5 - 6, 10, 7:20 - 28).
Christ intercedes for our sins with God the Father. When he returns there will be a union of church and state, of the king and high priest roles, in the divine Person of Jesus.
Against the Messiah
As an interesting side note regarding Christos, the English word "antichrist," which is used only in the writings of John (1John 2:18, 22, 4:3, 2John 1:7, etc.), comes from the Greek antichristos (Strong's #G500).
Antichristos means, as you would expect, someone who is against, in opposition to, a rival or adversary of, Jesus Christ. Quite literally, since Christos means "anointed one," the other word means someone not anointed by God, or someone who pretends to be so but is not (the antichrist).