...Nuns are monastics. Their vocation is to live a life of prayer within a cloistered convert and have little or no contact with the outside world.Sisters are those who belong to religious orders that have ministries out in the world.
Thanks! I learned something!
I found this, which probably explains some of why I, and I suspect many others, don't know this.
The most common misconception is that all sisters are nuns. This is not true. Both sisters and nuns are addressed as “sisters” which makes this confusing. For example, referring to a woman religious as Sr. Mary does not indicate whether or not Sr. Mary is a nun or a sister.So, sort of like the "Dr." case we are more familiar with. Mostly if you are introduced to someone as "Dr. Smith" you assume he's a medical doctor, but in fact he could be a dentist, or even a Ph.D. of some sort with pretensions of grandeur.
What you have described is, I think, unique to the Catholic Church, which of course are the vast majority of "Sisters" we have in the USA.
I think that the Orthodox Christians have Nuns, but not "Sisters" as a separate calling.
And, of course the Buddhists have a long monistic tradition as well. I don't think they are called "brother" and "sister" at all, though. There was one at college when I was there, but I don't remember this detail.
Thanks in return, because I learned something too. And I never really thought about what monastics are called in Buddhism. I’ll have to check that out.