system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What is the historical difference between monks, priests, and friars.

I was watching The Name of the Rose with Sean Connery, and the other day I was reading World Without End by Ken Follett.  I'm confused by the difference between these classes of religious people.  What were their roles?  Are some higher ranked than others?  Do their roles overlap?
gpt
A monk takes his vows and commits to a particular self-sufficient community consisting only of monks. He serves the church through devotion.

A friar takes his vows and commits to a larger area, a province, and is supported through donations. They will usually travel about their area and stay in a variety of places in the province they are committed to. He serves the church by working among laypeople.

A priest can be a friar, monk, or neither. He is an ordained member of the church which means he can perform rites and rituals such as giving mass, performing marriages, and giving last rites, things that a non ordained friar or monk cannot do.