Understanding Azure Cosmos DB APIs
Azure Cosmos DB is a globally distributed, multi-model database service. It supports multiple data models and APIs, allowing you to choose the API that best suits your application's needs and your development expertise. This flexibility ensures you can leverage your existing skills and tools while taking advantage of Cosmos DB's powerful features.
Core APIs
Cosmos DB offers several core APIs, each designed to work with specific data models and programming paradigms:

Core (SQL) API
The Core (SQL) API is the default and most commonly used API. It provides a rich, document database experience with a familiar SQL query language for querying JSON documents. It's ideal for applications requiring flexible schemas and powerful querying capabilities.
Learn more: SQL API Overview

Azure Cosmos DB for MongoDB
The API for MongoDB is a compatibility layer that mimics the MongoDB wire protocol. This allows you to use your existing MongoDB drivers and tools with Azure Cosmos DB, providing a fully managed, globally distributed MongoDB solution without the need for complex infrastructure management.
Learn more: MongoDB API Overview

Azure Cosmos DB for Apache Cassandra
The API for Apache Cassandra offers compatibility with the Cassandra query language (CQL). This enables you to migrate existing Cassandra applications to a fully managed, globally distributed database service, benefiting from its high availability and low latency.
Learn more: Cassandra API Overview

Azure Cosmos DB for Apache Gremlin
The API for Apache Gremlin provides a graph database solution. It uses the Gremlin traversal language to query and manipulate graph data, making it suitable for applications that model complex relationships, such as social networks, recommendation engines, and fraud detection.
Learn more: Gremlin API Overview

Azure Cosmos DB for Table
The API for Table is a key-value store API that is compatible with Azure Table Storage. It provides a schemaless data model and is designed for applications that need a simple, high-performance store for structured data.
Learn more: Table API Overview
Choosing the Right API
When selecting an API, consider the following:
- Existing Skillset: Do your developers have experience with SQL, MongoDB, Cassandra, or graph databases?
- Data Model: What type of data will you be storing? (Documents, key-value pairs, graphs, etc.)
- Querying Needs: What kind of queries will your application perform?
- Migration Strategy: Are you migrating an existing application?
Tutorials and Getting Started
Dive into our tutorials to get hands-on experience with each API:
- Get started with the Core (SQL) API
- Get started with the API for MongoDB
- Get started with the API for Apache Cassandra
- Get started with the API for Apache Gremlin
- Get started with the API for Table
Explore the documentation further to understand the specific features, SDKs, and tools available for each API.