Horus is an Egyptian god who is the son of Osiris and Isis. He was very important, especially in the transition from one Pharaoh to the next. The one who had just died was identified with Osiris and the new one was identified with Horus.
Despite claims by mythicists, Horus was not virgin born. His father Osiris had been killed by Seth and Isis used her magic to enable Osiris’s reproductive organs to work so that a child could be born. Horus did died and rise again but in a way much different from Jesus. As a child he was stung by a scorpion and because of the prayers of his mother, another god brought him back to life.
It is true that some early Christian artists used statues of Isis and baby Horus as a model for art depicting Mary and baby Jesus.