Does AdSense submit an HTML HTML page for analysis? If not, how?

Question

I am thinking of creating an ad network as an experiment and learning a new server language.

I don’t understand how Google AdSense knows what HTML is in a page. The request to googlesyndication.com seems to send them the current page URL, but not HTML. How then do they know what is on the page ?! Pages will look different for different users, even at the same URL. Some URLs will be behind passwords, but AdSense still displays relevant ads.

I do not understand what they are doing. Can you tell me how they do it?

Answer 1

Google, . Google Adsense → AdSense → .

, AdSense , . Google.

Answer 2

, Google , .