What is the difference between knowledge of the unseen and a righteous vision?

The knowledge of the unseen is divided into two types: absolute unseen, which only Allah knows, and relative unseen, which Allah may reveal to some of His servants. A righteous dream is what a righteous person sees in their sleep, consisting of glad tidings. It is an honor from Allah to His righteous servants. It has been narrated in the Hadith: "Nothing remains of prophethood except the glad tidings," and the glad tidings are "the righteous dream."