The name Gabriel means 'God's Hero,' and he is God's special messenger angel. On several occasions in the Bible, he has the job of coming to earth to give important announcements and tell special events. So it was Gabriel who had the amazing job of telling Mary that she would be the mother of Jesus.
The birth of Jesus took place like this. His mother, Mary, was engaged to be married to Joseph. Before they came to the marriage bed, Joseph discovered she was pregnant. (It was by the Holy Spirit, but he didn’t know that.) Joseph, chagrined but noble, determined to take care of things quietly so Mary would not be disgraced.
While he was trying to figure a way out, he had a dream. God’s angel spoke in the dream: “Joseph, son of David, don’t hesitate to get married. Mary’s pregnancy is Spirit-conceived. God’s Holy Spirit has made her pregnant. She will bring a son to birth, and when she does, you, Joseph, will name him Jesus—‘God saves’—because he will save his people from their sins.”