A REST API (Representational State Transfer Application Programming Interface) is an architectural style and a set of constraints that are used to create web services. RESTful APIs are designed to be simple, lightweight, and scalable, making them a popular choice for creating APIs that can be used by a variety of clients.
The REST architecture is based on a client-server model, where the client sends requests to the server, and the server responds with data. REST APIs use HTTP (Hypertext Transfer Protocol) to transfer data, which makes them easy to use with web-based applications.
REST APIs use a set of HTTP methods (verbs) to interact with resources. The most common HTTP methods used in RESTful APIs are:
- GET: Used to retrieve data from the server
- POST: Used to create new data on the server
- PUT: Used to update existing data on the server
- DELETE: Used to delete data from the server
RESTful APIs use a set of constraints to ensure that they are scalable and easy to use. These constraints include:
- Client-server architecture: The client and server are separate entities that communicate through requests and responses.
- Statelessness: Each request from the client to the server must contain all the information necessary to understand the request, and the server should not store any client state between requests.
- Cacheability: Responses from the server should be cacheable, to improve performance and reduce network traffic.
- Uniform interface: The interface should be uniform across all resources, to make it easy for clients to understand and use the API.
- Layered system: The API should be designed in layers, to improve scalability and flexibility.
RESTful APIs have become increasingly popular in recent years, due to their simplicity, scalability, and ease of use. They are used in a wide variety of applications, from mobile apps to enterprise systems.