The Hebrew name (Yesha'yahu) means "the Lord (YAHWEH) is salvation". The LDS Bible Dictionary describes Isaiah as "a prophet in Jerusalem during 40 years, 740-701 B.C." who had "great religious and political influence during the reign of Hezekiah, whose chief advisor he was". He was a martyr and the most quoted of all the prophets. The Lord promised that all of Isaiah's prophecies, whether concerning events of his day or of future events (or both), would be fulfilled. (3 Ne. 23:1-3) Many of Isaiah's prophecies have yet to be fulfilled.
Isaiah prophesied of Christ and taught of the universal need for repentance and obedience to God's law. Among other things, he also prophesied of the restoration of the house of Israel. The LDS Bible Dictionary explains that "A major difficulty in understanding the book of Isaiah is his extensive use of symbolism, as well as his prophetic foresight and literary style; these take many local themes (which begin in his own day) and extend them to a latter-day fulfillment or application. Consequently, some prophecies are probably fulfilled more than one time and have more than one application."
There have been many books written, and many commentaries made on the Book of Isaiah, including Elder Bruce R. McConkie's "10 Keys to Understanding Isaiah", Victor Ludlow's Isaiah: Prophet, Seer & Poet, and Avraham Gileadi's New Translation of the Book of Isaiah, complete with Apocalyptic commentary, but the greatest key to understanding Isaiah is the Holy Ghost or the Spirit of Prophecy (2 Ne. 25:4-5). The prophet Nephi declared that "in the days that the prophecies of Isaiah shall be fulfilled men shall know of a surety, at the times when they shall come to pass." (2 Ne. 25:7) Nephi also declared that Isaiah's words were recorded specifically for our time and for our benefit. (2 Ne. 25:8).
In his day, Nephi rehearsed (1 Ne. 15:20) and read (1 Ne. 19:23) the words of Isaiah to his people in order to "more fully persuade them to believe in the Lord their Redeemer". The LDS Bible Dictionary entry on Isaiah concludes with this promise and invitation: "The reader today has no greater written commentary and guide to understanding Isaiah than the Book of Mormon and the Doctrine and Covenants. As one understands these works better he will understand Isaiah better, and as one understands Isaiah better, he more fully comprehends the mission of the Savior and the meaning of the covenant that was placed upon Abraham and his seed by which all the families of the earth would be blessed."