Monks may be called brother but brothers do not necessarily have to be monks. Monks generally reside in abbeys. So, for example, we have a Benedictine abbey near here where the brothers are monks. They live and work at the abbey.
At the same time we have teaching orders (e.g. Christian Brothers, Brothers of the Sacred Heart) who do not reside in abbeys but in Brothers’ Residences. They teach in high schools.
Other orders serve in hospitals - like the Franciscans. They don’t live in an abbey, they live in an apartment complex (i.e Brothers’ Residence).
One joins a religious order after a period of discernment. You could probably get some good answers if you posted this on the Vocations thread.
