What is the main function of REST API and what is it used for in modern web applications?

REST API (Representational State Transfer Application Programming Interface) is an architectural style for creating web services that allows clients to interact with a server through standard HTTP methods (GET, POST, PUT, DELETE, etc.).

The main function of REST API is to provide a simple, scalable, and standardized way of exchanging data between the client and server.

In modern web applications, REST API is used for:

• Fetching and sending data between frontend and backend
• Integration with external services
• Enabling interaction between mobile applications and the server

Example of a REST API request in Go using net/http:

resp, err := http.Get("https://api.example.com/users/123")
if err != nil {
    log.Fatal(err)
}
defer resp.Body.Close()
// process response

Thus, REST API simplifies the development of distributed systems and provides flexibility in building client-server applications.