The term "Mother of God" refers to the title given to the Virgin Mary, the mother of Jesus Christ. This title emphasizes her role in the Christian faith as the one who bore the Son of God. It is a significant aspect of Marian devotion in various Christian denominations, particularly in Catholicism and Orthodox Christianity. The title is rooted in the belief that Jesus is both fully divine and fully human. The Council of Ephesus in 431 AD affirmed this title, declaring that Mary could rightfully be called the "Mother of God" because she gave birth to Jesus, who is God incarnate.