Creating and maintaining duplicate copies of data across multiple locations or servers for reliability and performance. Like having backup copies of important files in different buildings.
A global application replicates user data across data centers in different continents so users get fast access no matter where they are, and data is safe even if one data center fails.
All providers offer replication, but it’s implemented differently by service type: object storage replication copies buckets/objects to another region for durability and compliance; database replication (read replicas, geo-replication, multi-region) copies data to improve read performance and/or enable failover. Some options are asynchronous (lower cost/latency, possible lag) while others can be synchronous (stronger consistency, higher latency/cost).