SenseGuard works by modifying a network configuration file on your PC, called "hosts". It inserts several domain servers, used by Google Adsense, and tells your computer to ignore the domains if it comes across them in your web browser. Below is an example of what happens when your web browser views a page containing Adsense ads with SenseGuard turned on:
Your web browser opens a page containing the Adsense script in it. It requests Google's ad server to get the code to show for the Adsense ads. With SenseGuard active, the request is immediately ignored by your PC. Adsense ads will not display in your web browser. This is similar to if you had simply removed the Adsense script from your web pages, except that outside users viewing your site will still see your ads.