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02. 08. 2026 In modern web development, the data layer (backend) and the user interface (frontend or mobile application) are often built separately. For these components to exchange data seamlessly, we need a standardized interface. This is where REST API comes in—a set of rules and conventions that enables secure, stable, and transparent communication between different systems over HTTP protocol.
What Does REST Stand For and How Does It Work?
REST stands for Representational State Transfer. The basic idea of REST architecture is to treat every piece of data (user, product, order) as a resource accessed via a unique URL address and standard HTTP methods.
| HTTP Method | CRUD Operation | Description and Example URL |
|---|---|---|
| GET | Read | Retrieving data (e.g., GET /api/products) |
| POST | Create | Adding a new resource (e.g., POST /api/products) |
| PUT / PATCH | Update | Modifying an existing resource (e.g., PUT /api/products/42) |
| DELETE | Delete | Removing a resource from the database (e.g., DELETE /api/products/42) |
Main Principles of REST Architecture
For an interface to be considered RESTful, it must follow key architectural guidelines.
- Statelessness: The server does not store user session state. Every request must contain all the information needed for processing (e.g., authentication token).
- Client-Server Separation: The user interface and data storage are completely independent. You can redesign the entire frontend without altering the backend.
- Use of Standard Formats: Data is most commonly transferred in the lightweight and readable JSON format.
Example of a REST API Response in JSON Format
When a client sends an HTTP GET request to retrieve product data, the REST API responds with an appropriate HTTP status code (e.g., 200 OK) and payload formatted in JSON.
// HTTP GET /api/v1/products/105
// Status: 200 OK
{
"status": "success",
"data": {
"id": 105,
"name": "Arduino Uno R3 Kit",
"price": 24.90,
"currency": "EUR",
"in_stock": true,
"tags": ["arduino", "electronics", "beginner"]
}
}
Practical Use of REST API in IoT and Electronics
REST APIs are not just for web applications. They are also extremely useful for microcontrollers like the ESP32 or ESP8266. Your Arduino project can send sensor measurements (such as temperature or humidity) directly to your custom PHP REST API, which stores the data in a database and displays it on your web portfolio.