How were monks and friars different

The main difference is that a monk remains within his community while the friar has a public ministry. Generally speaking, once a monk enters the cloistered life, he does not leave. Friars are often given assignments in the world although they do have a communal life. This is why friars such as the Franciscans and Dominicans were very active in the evangelization of the New World while monks like the Benedictines established monasteries much later.