What is REST? What does RESTful mean?

REST (Representational State Transfer) is an architectural style for developing distributed systems, particularly web services. It is based on the use of standard HTTP methods (GET, POST, PUT, DELETE, etc.) and principles aimed at simplifying interaction between the client and server.

Main characteristics of REST:

• Client-server architecture
• Statelessness: each request contains all necessary information
• Caching
• Uniform interface (standardized way of interaction)
• Multi-layered system

RESTful is a service or API that follows REST principles. That is, it uses HTTP methods for operations on resources, where resources are identified by URIs.

For example, for working with the "user" entity:

• GET /users — get a list of users
• GET /users/123 — get the user with ID 123
• POST /users — create a new user
• PUT /users/123 — update user data
• DELETE /users/123 — delete a user

Thus, REST and RESTful describe an approach to building web services focused on resources and HTTP standards.