Cassandra is open source highly distributed NoSQL database with the industry proven performance and durability. Here are some of the features of Cassandra.

• Highly scalable: Cassandra allows the elastic scale, it allows to manage the hardware requirements of the system on the go. You can add/remove hardware depending on the traffic and requirements.
• No single point of failure: Cassandra is proven to be a highly available database and has no single point of failure built right in the core of the architecture.
• Linear scalability: Cassandra improves the throughput of the system as and when new Cassandra node is added hence it always improves the performance of the system and replicates the effect in hardware quickly.
• Data variety support: Cassandra supports the various data formats such as SQL, NoSQL, Unstructured data and it dynamically accommodate changes to your data structure depending on the need for the system.
• Transaction support: Cassandra supports the transaction for the atomic operation.

By using Cassandra API in CosmosDB, you avail all these features mentioned above with the following benefits as well provided by Cosmos DB.

• No management: CosmosDB provides you the API to manage your data and rest of the infrastructure is managed by CosmosDB.
• Automatic Indexing: CosmosDB by defaults creates the indexes for all the columns in the database, hence it improves the read time drastically.
• Global Distribution: CosmosDB allows you to distribute the database across the globe in a 30+ region using a single click of a button.
• Multiple consistency:  You can choose the consistency level from the strong, bounded-staleness, session, consistent prefix, and eventual. 

This covers all five data models supported by Cosmos DB. Let's go ahead and learn in brief about the consistency levels of Cosmos DB.