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What is a RESTful API?

Introduction

Before we delve into the world of Flask and RESTful APIs, it's important to understand what we mean when we say "RESTful API". The term REST stands for Representational State Transfer. It is an architectural style for distributed hypermedia systems and was first presented by Roy Fielding in 2000 in his famous dissertation.

What is a RESTful API?

An API (Application Programming Interface) is a set of rules and protocols for building and interacting with software applications. A RESTful API is an API that follows the principles of REST.

RESTful APIs are used to create web services, which allow different software applications to talk to each other in a standardized way. They are built using HTTP (Hypertext Transfer Protocol), which is the protocol used for transferring data over the internet.

Principles of REST

There are six guiding principles of REST:

  1. Client-Server Architecture: This principle states that the client and server should act independently. They can be developed separately as long as they know how to communicate with each other.

  2. Stateless: Every request from the client to the server must contain all the information needed to understand and process the request. The server should not store anything about the latest client request.

  3. Cacheable: Clients can cache responses. The responses themselves must be implicitly or explicitly defined as cacheable or non-cacheable to prevent clients from reusing stale or inappropriate data in response to further requests.

  4. Uniform Interface: The method of communication between the client and the server should be uniform. This simplifies the architecture as the overall system architecture is decoupled.

  5. Layered System: The system architecture can be composed of multiple layers, each with a specific functionality. Each layer cannot see beyond the immediate layer with which they are interacting.

  6. Code on Demand (Optional): Servers can provide executable code or scripts for the client to execute in its context.

How RESTful APIs Work

In a RESTful API, resources (like data objects or services) are identified by URLs, like http://example.com/users. To interact with these resources, components of the network (clients and servers) communicate via HTTP using methods like GET, POST, PUT, DELETE, and more.

  • GET is used to retrieve a resource.
  • POST is used to create a new resource.
  • PUT is used to update an existing resource.
  • DELETE is used to remove a resource.

Why Use RESTful APIs?

RESTful APIs have several advantages. They are stateless and thus do not require the server to remember the state of the application. This makes them scalable as they can handle large numbers of requests. They also use standard HTTP methods, which are understood by all internet-enabled devices. This makes them accessible and easy to use.

Conclusion

In summary, a RESTful API is a way of providing interoperability between computer systems on the internet. It is an architectural style that uses standard HTTP protocols and is scalable, stateless, and can be cached. In the following articles, we will explore how to build RESTful APIs using Flask.