Do you remember what types of clusters exist in MongoDB and what is the difference?

In MongoDB, there are two main types of clusters:

1. Replica Set — a group of multiple MongoDB servers where one is the primary, and the others are secondaries. The primary handles write operations, while secondaries replicate data from the primary. This provides fault tolerance and increases data availability.

2. Sharded Cluster — a distributed cluster that splits data across multiple shards (each usually a replica set). This allows horizontal scaling of the database, distributing load and data volume.

Main differences:

• Replica Set provides fault tolerance and data replication.
• Sharded Cluster provides scaling and load balancing by dividing data across shards.

Example: if your data volume and load are increasing, you can use sharding, and within each shard, a replica set for reliability.