Tagging?

I know this whole “tag” option is supposed to make our lives easier but I don’t understand the difference between tagging and favorites found on your internet webpage.  I have files there organized in different folders, for instance, under teacher sites are a list of regularly used websites and resources.  This is just one of many folders I have filled with websites relating to each other.  It’s all very organized and right there at my fingertips so how does this differ from tagging?