You can set whether information like income, profession, education, etc is used, + or - different topics/brands, as well as see the ads you’ve been shown in the past.
This feature that the OP posted about however is about doing all this in the browser instead of doing the tracking on their servers and across various websites with embedded analytics/tracking code. The end goal is also to get rid of third-party cookies entirely, hopefully shutting down that method of tracking, while still being able to provide targeted advertising.