Beginning in 1834, Smith began teaching the concept of priesthood "keys", and the requirement of literal priesthood ordination and a direct line of apostolic succession.
If needed, any number of additional counselors may be called to assist them, though the president of the church remains the only person on the earth authorized to use all priesthood keys.
It was begun with the restoration of the church in 1830 and continued with the restoration of all the priesthood keys of each prior dispensation.
Each quorum has a president of that quorum who holds priesthood keys.
If the recipient is being set apart as a president of a priesthood quorum, including a stake president or a bishop, "priesthood keys" are also conferred upon them.
The president of the Deacons Quorum is given priesthood keys to preside over the members of his quorum.
The Presidency of the Church presides over the entire church, and only the President of the Church is authorized to use all priesthood keys within the church.
Members of this quorum hold priesthood keys, but they are only used under the direction of the First Presidency.
Apart from the seven presidents of the seventy, seventies do not hold priesthood keys but are delegated the necessary keys to perform their duties.
The president is given "priesthood keys" to preside in his quorum.