What is Azure Cosmos DB?
Answer
Azure Cosmos DB is a globally distributed, multi-model NoSQL database service designed for low-latency, high-availability workloads. Key features: Global distribution: replicate data to any Azure region with a click; multi-region writes supported. Guaranteed low latency: single-digit millisecond reads and writes at any scale. Multiple APIs: Core SQL, MongoDB, Cassandra, Gremlin (graph), Table — migrate existing NoSQL workloads without code changes. Tunable consistency: five levels from strong to eventual. Automatic indexing: all properties are indexed by default. Serverless and provisioned throughput models. Cosmos DB is billed on Request Units (RU/s) — a currency that abstracts CPU, memory, and IO costs. Ideal for globally distributed applications, gaming leaderboards, retail catalogs, and IoT.