• Sharding is used to create a cluster of MongoDB instances consisting of at least three servers.
• There are three types of elements in Sharded Cluster.

1. 1. Shards
   2. Query Router
   3. Config server

Shards :

• It is a single MongoDB instance that holds a subset of the sharded data.
• It can be deployed as replica sets to provide redundancy and increase availability.
• The combination of multiple shards creates a complete data set.

Query router :

• Query router acts as a Mongos providing a stable interface between the application and the sharded cluster.
• In this MongoDB instance is responsible for routing the client requests to the correct shard.

Config Server :

• Config Server becomes to store the metadata (Data about the data) and the configuration settings for the whole cluster.