Purpose

In the HTTP protocol, there are two ways to send data: GET and POST.

Let's explore their differences and advantages and disadvantages.

Components of HTTP Request

[Scheme]://[Host]:[Port][Path]?[Query]#[Fragment]

[Header]

Example of HTTP URI Components

example.com:1030/software?id=test#section-4

Sending Data with GET

This method sends data by declaring parameters in the query section of the HTTP URI.

Example of GET

example.com?id=test

Advantages

• Can be cached in the URI, allowing for bookmarks, backtracking, etc.

• Faster than POST

• Parameter values are visible, so contents can be guessed.

Disadvantages

• Limited length for the URI

• Parameter values are visible, so contents can be guessed, making it less secure.

PHP Code to Receive Data Sent with GET

<?php
$data = $_GET['a'];
echo "$data";
?>

Sending Data with POST

This method sends data by declaring parameters in the header section of the HTTP request.

Example of POST

$name=Han is the parameter and data being sent.

POST /login HTTP/1.1
Host: www.example.com
Content-Length: 255
Cache-Control: max-age=242342
Upgrade-Insecure-Requests: 134423423
Origin: <http://www.example.com>
Content-Type: application/x-www-form-urlencoded

$name=Han

Advantages

• No length limit

• Parameter values are not visible, so it is more secure.

Disadvantages

• Cannot be cached, making it impossible to bookmark or backtrack.

PHP Code to Receive Data Sent with POST

<?php
$data = $_POST['a'];
echo "$data";
?>