A RESTful API is an architectural style for an application program interface (API) that uses HTTP requests to access and use data. That data can be used to GET, PUT, POST and DELETE data types, which refers to the reading, updating, creating and deleting of operations concerning resources.
RESTful APIs are designed around resources, which are any kind of object, data, or service that can be accessed by the client.
Key Principles of REST
- Stateless: Each request from client to server must contain all the information needed to understand and complete the request.
- Client-Server: The client and server act independently, each with clear roles.
- Uniform Interface: A uniform way of interacting with a given server irrespective of device or application type.
- Cacheable: Responses must define themselves as cacheable or not to prevent clients from reusing stale data.
When building RESTful APIs, focus on resources and how to properly represent them in your system. Use HTTP methods appropriately and maintain statelessness for scalability.