The religious are a tricky nature.
Obviously the major difference is that a brother is not a presbyter or a priest, he cannot celebrate the sacraments.
In terms of vows, each order and charism have different vows. Some charisms have both profess the same vows. (technically called promises as the vows are celibacy, obedience, and prayer) the promises can range from a monastic life to poverty. Some charisms have the priests take on more or less promises based on their duties, I.e. if the priest serves a monastary and the secular community he couldn’t promise poverty, because then he wouldn’t be able to get around.
Brothers, like nuns and sisters, are religious people that have consecrated their lives for the Kingdom of God. Their duties range based on the order. Some like Jesuits teach, some like the Franciscans help the needy.
Hope this helps