Hello,
For the first example above where you don't show the code, which I have included below;
<!DOCTYPE html>
<html>
<body>
<form action="demo_form_method_post.asp" method="post" target="_blank">
First name: <input type="text" name="fname"><br>
Last name: <input type="text" name="lname"><br>
<input type="submit" value="Submit">
</form>
<p>Click on the submit button, and the input will be sent to a page on the server called "demo_form_method_post.asp".</p>
</body>
</html>
This is more an example of how to send data to a server using a form, this does not have anything to do with jQuery. Also note that demo_form_method_post.asp from above is not of your control and you would have to have a web server of your own to process this ASP file. But any type of server side code would do here, a popular one is PHP.
Jim