Explain the principle of data replication and its main goals.

Data replication is the process of copying and maintaining up-to-date copies of data across multiple servers or nodes. The main goals of replication:

• Increased fault tolerance: if one server fails, data remains accessible on another.
• Load balancing: requests can be handled by different copies, reducing the load on the primary server.
• Faster data access: copies can be located closer to users.

Example: in a database, master-slave replication can be configured, where the master accepts writes, and slaves are read-only, which improves read performance.