Week 6:Tags,Social Bookmarking, and Folkso-what?

Ok...Tags I get, understand and like. In theory- the whole of this lesson I understand. In action-not so much. I was certain I grasped it until I began my Del.icio.us adventure. I signed up, logged in and jumped onto the confusion bandwagon. But I think I also discovered the error of my ways. In reading over the help topics from Del.icio.us this struck me; "The recommended way is to use one of our browser add-ons. Once installed..."If I'm right, I am completing the majority of these lessons while at work and on a network maintained by someone other than myself and I am guessing my installations my have limits. If I'm wrong, then...I'm clueless. Anyone who can shed light, please feel free to ease my flusteration.