Jesus was so named when he was circumcised (Luke 2:15-21). It means “Jehovah [God] is salvation.” Salvation is liberation or help from God. Jesus would save his people from their sins (Matthew 1:20-23). His name would be the hope of the whole world (Matthew 12:15-21). The disciples complained about those who healed in Jesus’ name without authority, but Jesus said not to stop them. Anyone doing a miracle in his powerful name is on our side (Mark 9:38-40). The Catholic Society of the Holy Name is a fraternity that prays for those who blaspheme the name Jesus. In Greek Jesus’ name is Ἰησοῦς [capitalized ΙΗΣΟΥΣ] pronounced yay-soos. The first three letters capitalized in Greek were a common abbreviation for Jesus ΙΗΣ. In our English alphabet, those letters are written IHS, letters used to decorate churches everywhere.
(References: http://www.biblestudytools.com | http://www.newadvent.org/cathen | http://christogenea.org)