ET or POST?
GET is simpler and faster than POST, and can be used in most cases.

However, always use POST requests when:

A cached file is not an option (update a file or database on the server).
Sending a large amount of data to the server (POST has no size limitations).
Sending user input (which can contain unknown characters), POST is more robust and secure than GET.
GET Requests
A simple GET request:

Example
xhttp.open("GET", "demo_get.asp", true)