What is a REST API?
A REST API (Representational State Transfer Application Programming Interface) is an architectural style for building web APIs that uses standard HTTP methods (GET, POST, PUT, DELETE) to perform operations on resources identified by URLs.
How Does REST API Work?
REST APIs are built on six principles: a client-server architecture, statelessness (each request contains all necessary information), cacheability (responses indicate if they can be cached), a uniform interface (consistent URL patterns and HTTP methods), a layered system (intermediaries like load balancers are transparent), and optional code on demand. Resources are represented as URLs (like /api/users/123), and HTTP methods define the action: GET retrieves data, POST creates resources, PUT updates them, and DELETE removes them.
REST APIs are the most common API architecture in web development, powering everything from social media platforms to payment gateways. In web hosting, most control panels, domain registrars, and cloud providers offer REST APIs for programmatic management. REST APIs are straightforward to cache using standard HTTP caching, easy to test with tools like Postman or curl, and well-supported by every programming language. Response formats are typically JSON, though XML and other formats are supported. REST API design best practices include using meaningful URL structures, proper HTTP status codes, pagination for large collections, and API versioning.