Messianic Judaism
Messianic Judaism is a movement of Jews who believe that Jesus (called by them with his Hebrew name Yeshua) is the Jewish Messiah, and who perform this belief in a Jewish way (observing the regulations of the Torah etc.). They are called Messianic Jews. The main branches of Judaism do not consider Messianic Judaism to be Judaism, but rather a form of Christianity, because Judaism rejects Jesus/Yeshua as the Jewish Messiah.
References
New religious movements
Jewish denominations
Christian movements and denominational families