What is the difference between GET and POST methods in HTTP?

GET is used to request data from a server. Data is transmitted in the URL as query parameters. GET requests are idempotent and can be cached.

POST is used to send data to the server for creating or updating a resource. Data is transmitted in the request body. POST requests are not idempotent and are not cached by default.

Feature	GET	POST
Purpose	Retrieve data	Send data (create/update)
Data	In URL (query parameters)	In request body
Idempotency	Yes	No
Caching	Yes	No (by default)
Security	Data visible in URL	Data not visible in URL
Data size	Limited by URL length	No strict limitations

// Example GET request
fetch('/users?id=123')
  .then(response => response.json())
  .then(data => console.log(data));

// Example POST request
fetch('/users', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({ name: 'John Doe', age: 30 })
})
  .then(response => response.json())
  .then(data => console.log(data));