Why are replication mechanisms used in databases or data storage systems?

Replication mechanisms in databases and data storage systems are used to enhance the reliability, availability, and performance of the system. Replication allows creating copies of data on multiple servers or nodes, which provides:

• Fault Tolerance: when one node fails, data remains accessible on another.
• Load Balancing: read requests can be distributed among replicas, reducing the load on the primary server.
• Increased Access Speed: data can be geographically closer to the user.

For example, in a distributed system, replication helps prevent data loss and ensures continuous operation during failures.