Answer:
Missions.
Step-by-step explanation:
In general terms, a mission can be termed as a form of assignment or job that a person has to undertake to bring about change. In the same vein, the term "mission" is also used by missionaries (which, by the way, is from where the term missionary originated) in their work to convert non-believers to Christianity.
Therefore, the settlements that were run or managed by friars to bring about a change in the culture of the local natives are called missions.