Azure Cosmos DB is Microsoft's globally distributed, multi-model database service. Where multi-model means Azure Cosmos DB supports multiple APIs and multiple data models, different APIs use different data formats for storage and wire protocol. For example, SQL uses JSON, MongoDB uses BSON, Table uses EDM, Cassandra uses CQL, Gremlin uses JSON format. As a result, we recommend using the same API for all access to the data in a given account.
Each API operates independently, except the API for Gremlin and NoSQL, which are interoperable.