Microsoft Azure DocumentDB is document based, schema free, NoSQL database. Microsoft Azure DocumentDB is a scalable and reliable database that maintains at least three copies of all data and stores each copy on a different physical server.
Microsoft DocumentDB database contains a set of collections. A collection is a set of JSON documents. A database in Microsoft DocumentDB can contain multiple collections. A document in a collection does not need to have the same set of fields or structure as another document in the same collection. A document can also contain nested documents.
The following schema is an example of a JSON document that Microsoft DocumentDB supports: