What is Siloing - Linking Only to Related Web Pages

Sage Lewis writes: Siloing is the idea of only linking out to other pages on your site and other outside resources that relate to that specific category or topic. So, if you had a cherry ice cream cone page, you would only link to resources discussing cherry ice cream cones. Information about chocolate ice cream cones and ice cream sundaes would either not be linked to or would be linked to using the nofollow tag. Link.