What is the difference between the HTTP protocol and the REST architectural style, and how do they interact?

HTTP is a data transfer protocol in a network that defines rules for message exchange between a client and a server. It describes methods (GET, POST, PUT, DELETE, etc.), headers, response codes, and message formats.

REST (Representational State Transfer) is an architectural style for building distributed systems that uses HTTP principles to organize interaction between clients and servers. REST defines a set of constraints such as:

• Using standard HTTP methods for resource operations
• Identifying resources via URIs
• Statelessness on the server
• Using resource representations (e.g., JSON, XML)

Thus, HTTP is a protocol, and REST is a way of using this protocol to create convenient, scalable, and easy-to-maintain web services. REST API is built on top of HTTP, utilizing its methods and capabilities to implement CRUD operations on resources.