Principles of REST
Representational State Transfer (REST) is an architectural style that defines a set of constraints and properties based on HTTP. Here are the key principles:
1. Statelessness
Each REST request from a client to a server must contain all the information the server needs to fulfill that request. This means that the server does not store any client context between requests.
2. Client-Server Architecture
REST architecture is based on a separation of concerns between the client and the server. This promotes scalability and allows for independent evolution of the client and server interfaces.
3. Uniform Interface
A uniform interface simplifies the architecture by having a consistent way of interacting with resources. This includes using standard HTTP methods such as GET, POST, PUT, and DELETE.
4. Resource Identification
Resources are identified by URLs (Uniform Resource Locators). Each resource should be accessible through a specific endpoint and represented in a format such as JSON or XML.
5. Layered System
REST allows for a layered system architecture where clients cannot ordinarily tell whether they are connected directly to the end server or an intermediary. This supports load balancing and shared caches.
6. Cacheability
Responses from the server must define themselves as cacheable or non-cacheable, improving efficiency by allowing clients to reuse stored responses.
7. Code on Demand (optional)
Servers can temporarily extend or customize the functionality of a client by transferring executable code (e.g., JavaScript). This is an optional constraint.
Understanding these principles helps developers create robust and scalable RESTful APIs that align with modern web standards.