MongoDb Sharding is a method used to distribute data to multiple machines. Sharding improves data access performance. if you want to install Sharded Cluster you may want to read below article.
Sharded Cluster Components
Sharding Cluster consists of three main components.
Shards in MongoDB
Its a MongoDB instance that stores a part of data from a collection according to a specific rule. Since data is divided into shards, there is an increase in performance because it will only redirect to the relevant shards during access. Shards can be a single mongod instance or they can be defined as replica sets for redundancy purposes.
Config Servers in MongoDB
These are the servers that stores the metadata of the cluster. Configuration servers are also mongod instances.
Routing Instances in MongoDB
These are mongos instances that allow applications to redirect read and write operations to shards. Applications cannot access shards directly. Routing instances are multiplexed on different servers to ensure high availability.