What are the components of a sharded cluster?
A MongoDB sharded cluster consists of the following components:
shard: Each shard contains a subset of the sharded data. Each shard must be deployed as a replica set.
mongos: The mongos acts as a query router, providing an interface between client applications and the sharded cluster.
config servers: Config servers store metadata and configuration settings for the cluster. Config servers must be deployed as a replica set (CSRS).