What are the major differences between Christianity and the Jehovah's Witness?

There are a small group of Jehovah’s Witness that drop by my house. I believe and pray to God and was raised half of my life as a Catholic and now consider myself to be a Christian. I am not interested in converting to Jehovah however I do not see many differences between the two studies. I spend most of my time learning about them and every now and again I can show them something that I believe in and why I believe what I believe. Can you help me figure these two things out?