Isaiah was a prophet under four kings of Judah, Uzziah/Azariah, Jothan, Ahaz, and Hezekiah. So basically, he was that guy who stands on the street corner and yells at everyone passing by about how they’re going to hell and how the world is going to end for over 50 years. This is a collection of his prophecies.
Isaiah preached that God told him that Judah was doomed. Doomed! For the usual stuff–the people had forsaken It, etc. Isaiah would stand there and tell anyone who would listen, and the empty air, when no one would, that God was going to burn Judah with fire and then let foreigners come in and rule it.
This land is Sodom and Gomorrah, Isaiah would yell. You are such sinners that God no longer accepts your sacrifices! It turns Its nose up at the smell of the burning bull and goat, at your incense! Repent, ye sinners!
Jerusalem is a whore, open to all comers! Isaiah ranted. It’s filled with murders and rebels. Everyone is greedy and oppress the poor! God will punish the city. It will burn out the wicked and restore the city’s righteousness.