Good evening, anyone with more affinity in PHP could explain the following code?
PS: I'm starting my studies so I apologize if the doubt is frivolous.
<?php
if (isset($_GET['pagina'])) {
$do = ($_GET['pagina']);
}else{
$do = "inicio";
}
if (file_exists("paginas/" .$do. ".php")) {
include("paginas/" .$do. ".php");
}else{
echo "Página não econtrada";
}
?>