Most links point to something that already exists—a file, a note, a webpage, or an email. Hookmark can do something different.
It can create a link to a search. Instead of linking to one item, it links to whatever matches your search whenever you open it. That means you can create a reusable search once and never have to remember exactly where something lives again.
Read more about it here:
Search links get more valuable over time because the search results evolve as your information grows.