I have always been puzzled about the differences between the following when it comes to male religious: brother, temporary deacon, permanent deacon, and monk.
“Brother” is an all-purpose name for a consecrated lay religious man.
A “temporary deacon” is usually called a transitional deacon and is a man who has been ordained a deacon as a preparatory step to being ordained a priest. Unless he is a member of a religious order, a transitional deacon is not a consecrated religious.
A “permanent deacon” is a man who has been ordained for the diaconate on a permanent basis, a position revived after the Second Vatican Council and open to married men. Because he is usually a man who has been ordained for parish and diocesan ministry, a permanent deacon is not a consecrated religious because he is not a member of a religious order.
A “monk” is a man who is a member of a religious order and has taken vows of poverty, chastity, obedience, and stability. Stability is a vow that he will remain at his order’s monastery for life. Monks are distinguished from friars in that friars do not take the vow of stability. A monk can be either a priest or a lay brother.