Azure Cosmos DB supports five consistency models or levels to provide enhanced performance and high availability of data stored. Cosmos DB provides customers with 100% consistency of the read requests for the selected consistency model.  Strong consistency: This consistency model guarantees linearizability. This means all requests are served concurrently, and the reads will return the most recent version of an item. It enables users to read only the latest committed write. This consistency model is most expensive.  Bounded staleness consistency: In this consistency model, reads from a secondary region may not return the latest version of a data item globally. However,  reads return the latest version of the data in that region. This model works well in cases where consistency and availability are not priority.    Session consistency: For Azure Cosmos DB, Session consistency is the default model. It is the most widely used mode across all regions. When a user goes to the location where a write was executed, they are guaranteed to get the most recent version of that data. It has the fastest throughput for reading and writing operations.    Consistent prefix consistency: In this model, single document writes have eventual consistency. Users will not see out-of-order writes in this consistent prefix consistency model. However, data here is not replicated across different regions at a fixed frequency.  Eventual consistency: This model provides the weakest consistency of all. This model provides no assurance that data is replicated within a set amount of time or a set version. Users may read data that is older than what they had read before. It offers the highest read latency.