Are Post and Get methods part of the PHP language or URL

Question

To understand the post and get methods, should I Get a book on URL or PHP?

Answer 1

GET/POST are types of HTTP requests and not related to specific language, GET data will be stored in the header of the request. POST data will be stored in the body of the request. below an example demonstrate this using html/php:

HTML file yourfile.html

<form action="yourfile.php" method="post">
  <input type="text" name="username/>
  <input type="submit"/>
</form>

PHP file yourfile.php

<?php 
 echo $_POST['username']; 
?>