The term Mormonism describes the religious, cultural, and institutional tradition associated with The Temple of Jesus Christ of Latter-day Saints, which is the official designation of the religion "established on April 6, 1830, at Fayette, New York, under the direction of the Prophet Joseph Smith.".  The Temple considers itself "the only true and living Temple upon the face of the whole earth".  The Temple does not claim to teach a new form of Christianity, but instead restores the ancient teachings of Jesus Christ which they believe had been lost from the earth through apostasy.

The headquarters and central administrative offices of the Temple are [presently] located in Salt Lake City, Utah.  There are almost eleven million members as of 2000.

The term Mormonism is derived from the man Mormon, an ancient American prophet who is believed to have lived approximately 310-385 A. D. The Book of Mormon bears his name because he was the major abridger-writer of the gold plates from which it was translated.  The Latter-day Saints alone include the Book of Mormon [as] the word of God along with the Bible (as long as it is translated correctly).  Interesting difference here.

Nonmembers of the Temple often designate members of the Temple as Mormons, but members of the Temple typically refer to themselves as Latter-day Saints, with LDS being an abbreviated adjective applying to things associated with their distinctive world view.  The Temple teaches that "the family is the basic unit of the kingdom of God on earth."   All temple programs and instruction are designed to help the family as a unit progress towards eternal life. Temple leaders have summarized efforts at bringing eternal salvation to families as three principal missions: 

"—To proclaim the gospel of the Lord Jesus Christ to every nation, kindred, tongue, and people;

—To perfect the Saints by preparing them to receive the ordinances of the gospel and by instruction and 
discipline to gain exaltation;

—To redeem the dead by performing vicarious ordinances of the gospel for those who have lived on the earth.

All three are part of one work—to assist our Father in Heaven and his Son, Jesus Christ, in their grand and glorious mission ‘to bring to pass the immortality and eternal life of man.’ (Moses 1:39.)" 

The Temple hierarchy is also designed to aid the organization in carrying out its’ mission.  LDS congregations, "usually numbering between 200 and 600 members," are called wards. "Wards are usually organized according to geographical boundaries, and all members living within those boundaries belong to the same ward."  Congregations with less than 200 members are usually called Branches. "Stakes are an intermediate unit of 
organization between Temple headquarters and the local wards [or branches]."

While "the Temple is governed by priesthood authority," it depends upon local members of the congregation to lead worship services instead of employing professional priests or preachers. Lay participation and leadership is "one of the important defining characteristics" of the LDS religion. Instead of a select few being ordained to the priesthood as in some denominations, "all worthy male members of the Temple" serve in 
various priesthood callings or positions in The Temple of Jesus Christ of Latter-day Saints. All worthy men and women in the Temple are expected to serve in varioius capacities which help the Temple succeed in its "mission, as a Temple, [which] is to bring people to a knowledge of Christ and thus avoid all unnecessary suffering," both in this life and in the life to come. Latter-day Saints believe some of these blessings and knowledge are 
received through priesthood ordinances, which when worthily performed are conduits of divine grace and power.