A chapel is a small place of worship. It may be within the grounds of a larger church or cathedral or free-standing.

A monastery is a complex (which may house a church or chapel(s) that serves as a residence for a brotherhood of monks.

@marinelife
Sorry one more a cathedral.

From the wiki: “A cathedral (French cathédrale from Lat. cathedra, “seat” from the Greek kathedra (καθέδρα), seat, bench, from kata “down” + hedra seat, base, chair) is a Christian church that contains the seat of a bishop.”

church
a building for public Christian worship

chapel
1.a private or subordinate place of prayer or worship; oratory
2.a separately dedicated part of a church, or a small independent churchlike edifice, devoted to special services

monastery
a house or place of residence occupied by a community of persons, esp. monks, living in seclusion under religious vows

cathedral
1.the principal church of a diocese, containing the bishop’s throne
2.(in nonepiscopal denominations) any of various important churches

Church may also refer to a particular congregation, meaning the people who attend services at a particular place of worship,so it would be appropriate to say “The church is having a picnic today at the park.” Obviously a building doesn’t have picnics. Also, The Church (capital C) can refer to all people of the Christian faith.