从PHP文件加载内容

I have searched stack overflow for this question but im not even sure what its called or how to achieve it so this may be a useless question for others, if so apologies for that, like mentioned I don't even know the correct name for it.

I was looking though a site and their sub-nav links are loaded from one file. If you click on home it will load the links and if you click radio it will load the links from one file.

$("#subNav_menu").load("./templates/subnav.php?menu=home");
$("#subNav_menu").load("./templates/subnav.php?menu=radio");

I'm not sure how to achieve this, could anyone provide me with some guidance and an example?

He is loading a php file with some parameters. in this example:

//test.html
<a href="test.php?name=home">home!</a>
<a href="test.php?name=radio">radio!</a>

php file:

//test.php
echo $_GET["name"]; // will give out "home" or "radio" depends on clicked

I think in his .php file he is loading content.