I\'m trying to find useful tutorials about how to create modern websites that loads content without refreshing the page.
I have tried all kinds of words in Google, but I
tl;dr:
Googling ajax website tutorial or jquery address tutorial is a good start.
As has been noted, the key here is AJAX.
AJAX alone, however, is not the answer. It's pivotal to a non-page-reload site, but there are also a lot of other things to consider.
Luckily for us all, the Internet is great, and lots of developers have an open-source is awesome mindset.
Suffice to say, this type of site has been done before, and there are people out there who have made developing a site like this easier.
Ignoring the back-end & server-side setup, the way I would recommend starting a site like this is to use the following:
Use the plugin from the start; from experience, it's difficult to implement it after you've completed the site.