Section 84 is commonly known as the Oath and Covenant of the priesthood.
“And…all they who receive this priesthood receive me…and he that receiveth me receiveth my Father…and this according to the OATH and COVENANT of my Father, which he cannot break, neither can it be moved.” (D&C 84:33-44)
So what is the difference between the oath and the covenant?
It takes two parties to make a covenant, but any person can swear an oath. Man and deity enter into the covenant of the priesthood, but only the Lord, meaning the Father, swears an oath. (Bruce R. McConkie, A New Witness for the Articles of Faith, pg. 313)