We gain most of our understanding about translated beings from 3 Nephi 28:
In verses 13–15 Mormon explained that translated beings are also transfigured. Elder Bruce R. McConkie defined this state as follows:
“Transfiguration is a special change in appearance and nature which is wrought upon a person or thing by the power of God. This divine transformation is from a lower to a higher state; it results in a more exalted, impressive, and glorious condition… .
“By the power of the Holy Ghost many prophets have been transfigured so as to stand in the presence of God and view the visions of eternity. Speaking of such an occasion in his life, Moses recorded: ‘Now mine own eyes have beheld God; but not my natural, but my spiritual eyes, for my natural eyes could not have beheld; for I should have withered and died in his presence; but his glory was upon me; and I beheld his face, for I was transfigured before him.’ (Moses 1:11; D. & C. 67:11.) …
“Similarly, when the Three Nephites ‘were caught up into heaven, and saw and heard unspeakable things, ’ they were transfigured”
(Mormon Doctrine, p. 803).
The difference, then, between transfiguration and translation is that transfiguration is more temporary. The Three Nephites were transfigured for a time so that they could view the visions of eternity. They were also translated, which condition is of a longer duration, until the Judgment Day.