Azure Cosmos DB vs Google Cloud Spanner

Azure Cosmos DB is a globally distributed, multi-model database service by Microsoft offering single-digit millisecond latency and 99.999% availability SLA. It supports document, key-value, graph, and column-family data models with multiple API options.

Cloud Spanner is Google's horizontally scalable relational database service that combines the benefits of traditional SQL databases with the scalability of NoSQL systems. It provides strong consistency and global distribution for mission-critical applications.