Priesthood and Line of Authority
Scriptures describe figures being ordained to the priesthood. Examples include Aaron, Joshua, the 12 Apostles, and Joseph Smith and Oliver Cowdery. The Priesthood can only be conferred on another by one holding the same priesthood who is authorized by Priesthood keys.
In the book of Doctrine and Covenants, there are a few revelations that provide information about the ordaining of men to the Priesthood during the time of the Genesis Patriarchs and the lines of authority of Moses and John the Baptist.
What’s the point?
Studying the Priesthood, its history, and mechanisms is important in understanding the influence of the Priesthood in our life. Also, we can see that it is important knowing where authority comes from. When Priesthood is passed down in righteousness, God is with his people. When the Priesthood is passed down in unrighteousness, or from those who do not have the authority, people are in Apostasy.
Here is a link to the diagram.