What is the Mormon religion?

The Mormon religion (the Church of Jesus Christ of Latter-day Saints) is a Restorationist Christian Church. Like other Christian Religions, they have a central focus on Jesus Christ and salvation through Him. They also have some very unique beliefs, such as modern day prophets. You can learn more about the basic doctrines and beliefs of the Church by visiting Mormon.org.

These are the Church's "Articles of Faith" written by Joseph Smith.

1. We believe in God, the Eternal Father, and in His Son, Jesus Christ, and in the Holy Ghost.
2. We believe that men will be punished for their own sins, and not for Adam's transgression.
3. We believe that through the Atonement of Christ, all mankind may be saved, by obedience to the laws and ordinances of the Gospel.
4. We believe that the first principles and ordinances of the Gospel are: first, Faith in the Lord Jesus Christ; second, Repentance; third, Baptism by immersion for the remission of sins; fourth, Laying on of hands for the gift of the Holy Ghost.
5. We believe that a man must be called of God, by prophecy, and by the laying on of hands by those who are in authority, to preach the Gospel and administer in the ordinances thereof.
6. We believe in the same organization that existed in the Primitive Church, namely, apostles, prophets, pastors, teachers, evangelists, and so forth.
7. We believe in the gift of tongues, prophecy, revelation, visions, healing, interpretation of tongues, and so forth.
8. We believe the Bible to be the word of God as far as it is translated correctly; we also believe the Book of Mormon to be the word of God. (The Church uses the King James Version of the Bible in English speaking countries)
9. We believe all that God has revealed, all that He does now reveal, and we believe that He will yet reveal many great and important things pertaining to the Kingdom of God.
10. We believe in the literal gathering of Israel and in the restoration of the Ten Tribes; that Zion (the New Jerusalem) will be built upon the American continent; that Christ will reign personally upon the earth; and, that the earth will be renewed and receive its paradisaical glory.
11. We claim the privilege of worshiping Almighty God according to the dictates of our own conscience, and allow all men the same privilege, let them worship how, where, or what they may.
12. We believe in being subject to kings, presidents, rulers, and magistrates, in obeying, honoring, and sustaining the law.
13. We believe in being honest, true, chaste, benevolent, virtuous, and in doing good to all men; indeed, we may say that we follow the admonition of Paul-We believe all things, we hope all things, we have endured many things, and hope to be able to endure all things. If there is anything virtuous, lovely, or of good report or praiseworthy, we seek after these things.

First thing, to be correct, it would be the "Mormon Religion." It would also be called "The Church of Jesus Christ of Latter Day Saints." When you ask what it is, I'm assuming you are asking what the Mormon beliefs are, and what they do. Mormons believe in Jesus Christ, thus the name and the fact that they ARE christian. They also believe in The Book Of Mormon. Some get this part confused, they think Mormons had replaced the bible with their own "Golden Book." This is not true, the Mormons also believe in the bible that you all know of. If you have other questions in what we believe in, read the Thirteen Articles Of Faith.