If you are chooosing what religion to follow, I would strongly recommend you the Orthodox church. Its priests try to help people (rather than to church), and your soul can always find comfort and consolation there. They also have a sincere and orthodox belief in the God. I must also add that every year the God himself sends human a sign that the Orthodox church is the correct religion: you may want to look up the article "Holy Fire" in Wikipedia. Please, note that the God sends this fire only to priests of the Orthodox church. When priests of other churches tried to get it, they failed.

One can easily write books about these differences. It is pretty easy to trace differences between the Catholic and the Orthodox churches, because the two are very close to each other and have Catechisms, where their main points are presented succinctly. I have studied some parts of these, and I have no idea about Protestantism. The main points of the Catholic religion, rejected by the Orthodox church: 1. Filioque (different understanding of some aspect of Holy Spirit) 2. Immaculata conceptio (some subtle points about the birth and sins of Virgin Mary) 3. Papal infallibility (Pope can't make a mistake; this is not accepted by the Orthodox church and Protestants) 4. Purgatory (Orthodox church and Protestants reject its existence) 5. Munificentissimus Deus (Virgin Mary came to heaven together with her body - rejected by the Orthodox church) I am also not certain about the role played by icons and vitas of saints in the Catholic church. These are very important in everyday's life of orthodox christians. Apart from this, there are also significant differences in ways how people actually praise the God, as well as in organization of churches. Modern Catholic church is becoming more and more liberal and democratic (and less "religious"), concentrating on "teachings" in order to attract more parishioners, while the Orthodox church keeps itself in the most traditional, classical form - it doesn't change with time.

IT is difficult to really list all the differences between them individually. Broadly, they all have different interpretations of the teachings of Jesus and how to follow those teachings.

Don't even THINK of asking that type of question.

这些宗教的不同之处就太多了吧，真不好说，Google、百度一下吧