What is a REST API and why is it useful?

Reading time

6 min.


api rest

What is an API?

An API, or Application Programming Interface, is a set of rules and protocols that enable different software applications to communicate with each other. It defines the methods and data structures that developers can use to integrate the functionalities of one application into another.

In other words, an API acts as a bridge between two separate pieces of software, facilitating the exchange of information and enabling different applications to work together coherently. APIs can be used to access online services, interact with databases, integrate third-party functionality, or even connect physical devices.

There are different types of API, including Web APIs, often based on HTTP/HTTPS protocols, and software library APIs, which enable developers to access specific functionalities of an application or system. APIs play a central role in modern software development, promoting modularity, code reusability and seamless integration between different technologies.

What is REST architecture and how does it work?

REST (Representational State Transfer) architecture is an architectural style for the development of web services. Conceived by Roy Fielding in 2000, REST proposes a set of simple principles for the design of distributed systems, emphasizing scalability, simplicity and interoperability between software components. Key principles of REST architecture include:

Resources identified by URIs

Each entity or data set accessible via the API is considered a resource. Each resource is identified by a URI (Uniform Resource Identifier), which is a unique address. For example, in a user management API, a resource could be identified by a URI such as /users/123.

Using HTTP Methods

Operations on these resources are performed using standard HTTP protocol methods. The four main methods used in a REST API are: GET (Retrieve data from a resource), POST (Create a new resource), PUT (Update an existing resource), DELETE (Delete a resource).

Resource representation

The data associated with a resource is represented in a specific format, often JSON (JavaScript Object Notation) or XML (eXtensible Markup Language). When a client makes a request, the server returns the appropriate representation of the resource data.


The REST architecture assumes that each request from the client to the server contains all the information needed to understand and process the request. The server does not store the client’s state between requests, which means that each request is independent of the previous ones.

HTTP responses

The server responds to client requests using the appropriate HTTP status codes. For example, a 200 OK code means that the request was successful, 404 Not Found indicates that the requested resource was not found, and so on.

HATEOAS (Hypermedia As The Engine Of Application State)

Some REST services follow the HATEOAS principle, where the server includes hypertext links in responses to guide the client to other associated resources. This allows the client to navigate dynamically through the API.

What is the purpose of the REST API? 10 Use cases :

A REST API (Stateful Application Programming Interface) is used to enable communication between different software systems via the HTTP protocol. Here are some of the main uses and functions of a REST API:

1. Web Services Integration

REST APIs facilitate integration between different web services, enabling separate applications to communicate and share data in a standardized way.

2. Web Application Development

Developers use API REST to build interactive and dynamic web applications. These APIs enable front-end applications to communicate efficiently with back-end servers to retrieve, update or delete data.

3. Mobile

Mobile applications can use REST APIs to access functionality and data from a server, facilitating the development of connected mobile applications.

4. Internet of Things (IoT)

IoT devices can use REST APIs to exchange data with servers, enabling remote collection, monitoring and control of connected devices.

5. Data access

REST APIs are commonly used to enable developers and applications to access datasets, be they weather data, databases, cloud services, and so on.

6. Microservices

Microservice architecture is often based on REST APIs. Each microservice exposes an API that can be called by other services, promoting modularity and scalability.

7. Social networking platforms

Many social media platforms provide REST APIs that enable developers to create applications that interact with these platforms, for example, to post updates, retrieve profiles and so on.

8. E-Commerce

E-commerce sites frequently use REST APIs to manage functionalities such as shopping carts, payment processing, order management and so on.

9. Distributed systems

REST APIs facilitate communication between software components distributed across different servers, which is essential in cloud environments and distributed architectures.

10. Application Development

Developers use REST APIs to build functionality into applications without having to reinvent the wheel. This saves time and makes efficient use of existing services.

Our software suites, SDKs and sample codes enable you to integrate, parameterize, activate and disable our beacons and sensors.


8 Advantages of the REST API :

1. Simplicity and lightness

REST architecture is simple to understand and implement. It uses HTTP protocol standards and is based on fundamental concepts, making it lightweight and easy to use.

2. Interoperability

REST APIs promote interoperability between different systems and programming languages. By following standard conventions, they enable applications developed in different environments to communicate consistently.

3. Scalability

REST APIs are highly scalable. They allow new functionalities to be added without disrupting existing ones, favoring the harmonious growth of applications, particularly in the context of microservice architectures.

4. Flexibility

REST APIs are flexible in terms of data representation. They can return data in JSON, XML or other formats, depending on the needs of the client application. This allows developers to tailor responses to specific requirements.

5. Cache facility

REST servers can take advantage of the HTTP protocol’s caching mechanisms. This improves performance by storing responses to frequent requests locally, thus reducing the load on the server.

6. Client-server separation

REST architecture encourages the separation of concerns between client and server. This separation simplifies the maintenance and evolution of systems by enabling updates to be carried out independently of the client and server.

7. SEO-Friendly

Applications using REST APIs to retrieve dynamic client-side data can improve their SEO. Search engines prefer sites that offer fast, interactive user experiences.

8. Security

REST APIs can be secured by using protocols such as HTTPS and by implementing authentication mechanisms such as access tokens. This guarantees secure data exchange between client and server.


In short, REST APIs offer a flexible, simple and high-performance approach to communication between systems, enabling the creation of modern, scalable and interconnected applications.

Vighnesh GHARAT
Electronic Engineer
An electronics engineer specializing in radio frequency at ELA Innovation in Montpellier, Fabien studied at the University of Montpellier, where he received his Master’s degree in Sensors and Associated Systems (CSA) in 2012. He then completed his PhD at the Institut d’Electronique et des Systèmes (IES) in collaboration with the Institut National de la Recherche Agronomique (INRA) on the Study of dielectric properties of polymers and their use as biosensors on passive ultra high frequency RFID tags. He received his doctorate in 2015 from the University of Montpellier. He is now in charge of the normative and testing aspects of ELA Innovation products.
Latest posts

Boostez votre
projet de géolocalisation !

Plongez dans le monde des technologies de localisation : BLE, Wirepas et Quuppa. Optimisez vos processus & prises de décision


ELA Innovation wishes you happy holidays!

Annual closure

December 25 to January 2, 2024


January 2 to 5, 2024

Deliveries will resume from January 8, 2024.

Boost your
telematics project

Discover how to monitor, track and secure vehicle fleets using Bluetooth sensors and beacons.

brochure transport et télématique mockup

ELA Innovation • All rights reserved

Contactez-nous directement en utilisant le formulaire ou cliquez sur le bouton ci-dessous pour faire une demande de devis :