A clickstream is the trail you leave when you move around the internet: which sites you opened, which pages you looked at, in what order, and often how long you stayed. It is called a stream because the clicks come one after another, like water in a line. Internet providers and many websites collect this. Shops and ad companies use it to see what people like, where they get stuck, and what to show next. Though actually, it is not only clicks. The record can include searches, the back button, and time on a page; clickstream has become a handy name for that whole path. The same trail that helps a shop can also show quite a lot about a person, so the word sits next to privacy.