What's the difference between synchronous and asynchronous replication?

The choice that states synchronous replication sends data at the same time it is created, while asynchronous replication sends data periodically, accurately describes the fundamental difference between the two replication methods.

In synchronous replication, data is written to both the primary and secondary storage at the same time, ensuring that both locations have the same data instantaneously. This method is crucial for applications where data consistency and integrity are paramount, such as in financial transactions or real-time data processing. The risk of data loss is minimized because changes are not considered complete until they are confirmed at both locations.

Conversely, asynchronous replication involves a lag between the data being created and the moment it is written to the secondary site. This method is generally used in scenarios where the speed of data writing to the primary storage is prioritized over immediate consistency with the secondary storage. It can be beneficial for disaster recovery solutions, where slight delays in data synchronization are acceptable.

The contrast between these methods is important for understanding how data management and recovery solutions operate in different environments.