What is sharding and replication? What are they used for?

Sharding is a method of horizontal scaling of a database, where data is divided into parts (shards), each stored on a separate server or cluster. This allows distributing the load and increasing the volume of data processed.

Replication is the process of creating copies of data from one server (master) to other servers (replicas). Replicas provide fault tolerance, increase data availability, and allow load distribution for reading.

In summary:

• Sharding is needed for scaling and improving performance with large data volumes.
• Replication is necessary for backup, increasing availability, and scaling reads.