You can store variables within the URL. for example:
That would load mydomain.com with the variables of name = Jamy and favfood = Pancakes.
You could fill out a form, click submit and the next page could be loaded with info you typed stored in the URL. It could then greet you. “Hi Jamy”, etc.
This is done via PHP’s $_GET. Have a look at this: http://php.net/manual/en/reserved.variables.get.php