What's The Difference Between Christianity And Catholic?

I was not aware that there is a difference here. Catholics are Christians and as such follow the teachings of Jesus Christ.
I guess the answer to your question is:
All Catholics are Christian but not all Christians are Catholic.
Is that a true enough statement for you ?

To my knowledge, cristianity follows both the old and new testement. Catholics have a few extra books in between the old and new testement. These books tell them to pray to saints, who in turn deliver that prayer to God. Whereas christians pray directly to God, in the name of Jesus. Both are considered christian.

I want to give you facts not a guess...
Christianity: en.wikipedia.org
Catholics: en.wikipedia.org

Dabossman is correct.  catholics are christians, because they base their religion on the teachings of christ.  they are one sect of christianity.  protestants are another sect, and they are probably what you mean when you make a distinction between Christians and catholics, altho this is incorrect.  both follow the teachings of christ, hence both are christians.

It depends on how you define Christianity, if you define it: Anyone who believes in Christ (in other words  he existed) or anyone who believes Christ to be the one and only saver, the living and true God, who died for our sins, was raised from the dead, is now in heaven, and one day will come back to judge us.

If you define it as the first then yes Catholics are Christians.

If you define it as the second then:
Catholics believe that baptism saves.
Christians believe that believing in Christ is the one and only way to salvation.

Catholics believe that when Mary was conceived she was sinless.
Christians believe that only Jesus was without sin

Catholics believe that the Pope is infallible
Christians believe that all humans are fallible

Catholics believe that when taking communion the bread and wine turn into Christ's blood and body!
Christians believe that the bread and wine are a symbol representing  Christ's blood and body and our a reminder of His death and our utter helplessness without Him.

Catholics pray to the saints, not just God.
Christians pray to God alone.

Catholics believe in a place they made up called Purgatory and that people go there after death and are held there, not allowed to go to heaven.
Christians believe there is no such place and that after death you ether go to Heaven or Hell.

These are just some of the differences I was about to go on but I just got called away, so I hope you understand this and it is helpful!

Well I think that they believe in the same principles. Just that Catholics worshiped Mary and the saints were christians they don't worship them as much as the Catholics.

They are similar but not the same. Catholics are more "religious" than christians. Catholics can't get married, they worship Mary, and they fear or view the devil more than they should. They believe rules, regulations, and policies will get you into heaven.Christians on the other hand are radical but normal people. They believe in marriage and life outside of Priest school, I am a devout Christian and up and coming preacher who is dedicated to Christ and the work of the ministry but i like to do stuff like go to the mall, watch a movie, and I look foward to marriage! In other words I love God but I do have a life. Most clergy and dedicated catholics don't. I do believe catholics will go to heaven but I don't think they will have much fun on earth.As a christian we also believe heavily in the blood of Jesus and the power of the Holy Spirit.