https://thehiddenwiki.org is a website that provides you the onion links.
Now what is an onion link??
Onion links are the links that you can access only using tor (The Onion Router)browser.Tor browser makes sure that you remain anonymous while surfing the web whereas other browsers keep track of you while surfing.
You can access thehiddenwiki.org from any browser but the onion links in this website can only be accessed using tor.
BONUS => You cannot post comments on instagram containing "thehiddenwiki.org".