Categorization is order, tagging is chaos. No order is perfect, but it enables people to talk about the same entities and to agree on certain ideas. Tagging is

Categorization is order, tagging is chaos. No order is perfect, but it enables people to talk about the same entities and to agree on certain ideas. Tagging is when everyone invents their own labels and conventions, requiring tons of "smart" algorithms to make sense of the mess.