Hovering over links in a google search displays a different URL

Question

I have noticed that when hovering over search result links in Google that the status bar shows the correct url for the website being linked to, when I then proceed to inspect the element of that link I notice that the href on that link is a Google relative link and, if I hover over it again the status bar updates with the new website URL.

Can anyone shed some light on how this works please?

Answer 1

When you click on it, Google use JS to change the href attribute (ref_to_a_element.setAttribute('href', '/foo') to point to their own server so that they can redirect you through it and track your visit.

It is the type of deceptive content masking that they penalise other people for.