Google's Privacy Sandbox
The Privacy Sandbox is a new advertising platform created by Google designed to create a more private way of tracking a user's interests for advertising.
Instead of using third-party cookies placed by different advertisers and tracking companies, the Privacy Sandbox will locally compute a user's interests directly within the browser, currently only used in Google Chrome.
Advertisers using the new Privacy Sandbox can request visitors' interests to show a relevant ad, with the browser replying with anonymous data that lists the categories the user is interested in.
These interests are computed from the user's browsing history, where are sites are associated with various subject categories, such as College sports, Razors & shavers, Ice skating, Comics, Bodybuilding, etc.
The Privacy Sandbox is broken up into three components named Ad Topics, Site-suggested ads, and Ad Measurement, as described below.