The LOD browser switch let's you, the user, decide which of the growing number of browsers for the Web of Data you want to use. You probably came here because some website linked to us. The website also probably already filled out the box on the top for you. Now you can just select one of the many browsers from the page and try them out to explore the growing Web of Data (if you want to try it out now, you can click your browser's back button in order to retain the URI already entered).
Once you tried the options you may want to save your selection in your browser (by ticking the check box at the bottom), so that next time you will be automatically taken to your selection. You can come back any time and change your selection, or delete it (by choosing 0 days for the time frame).
If you want to learn more about the Web of Data, you can go to the Linked Data project page, or read more at the W3C Semantic Web page.