JOEL - Generally speaking an endowment is a gift, but in terms relating to the Church of Jesus Christ of Latter-day Saints, it is a course of instruction, ordinances, and covenants that are given to LDS members in dedicated temples. According to The Encyclopedia of Mormonism, "The words "to endow" (from the Greek enduein), as used in the New Testament, mean to dress, clothe, put on garments, put on attributes, or receive virtue." The Temple Endownment was given to the prophet Joseph Smith through revelation from God.
According to Joseph Smith, the Endowment gives "a comprehensive view of our condition and true relation to God" (Teachings of the Prophet Joseph Smith, p. 324), "to prepare the disciples for their missions in the world" (p. 274), to prevent being "overcome by evils" (p. 259), to enable them to "secure the fulness of those blessings which have been prepared for the Church of the Firstborn" (p. 237).
The sacred nature of the Endowment prevents a discussion of the details of what is involved in the ceremony, but a simple outline of the ordinance can be described as including four main parts:

1. Preparatory ordinance. This involves a ceremonial washing and anoiting and dressing in the sacred temple clothing.
2. A course of instruction that teaches the member about the creation of the universe, our world, Adam and Eve and God's dealings with them. We are reminded about the plan of salvation and our role in it as well as other points of doctrine.
3. Making covenants. Members make promises to God "to observe the law of strict virtue and chastity, to be charitable, benevolent, tolerant and pure; to devote both talent and material means to the spread of truth and the uplifting of the [human] race; to maintain devotion to the cause of truth; and to seek in every way to contribute to the great preparation that the earth may be made ready to receive…Jesus Christ" ("House of the Lord",Talmage, p. 84).
4. A sense of devine presence. One feels the presence of God and the Holy Ghost in the temple. There is an aura of deity manifest to the worthy individual. Temple ordinances are seen as a means for receiving inspiration and instruction through the Holy Spirit, and for preparing to return to the presence of God.

All who wish to be exalted in the highest kingdom of God following the resurrection must receive their own Endowments in the temple. Living members can stand in as proxy for those who have died and perform the ordinances on their behalf.