The more stuff you have open (or habitually leave open) in an application, the more it becomes part of your consciousness, an extension of your mind. For many of us, the question “What are you doing right now?” could best be answered by, “Here’s a list of the tabs I have open in my web browser.”
Hackers* use the word “state” to describe “information being maintained in non-permanent memory”, whether that memory is in a human skull or a computer’s RAM chips. In fact, that ambiguity over exactly where the state is being maintained is one of the word’s strengths — as the browser-tabs example shows, there’s getting to be less of a distinction between the two. The stuff in my browser’s tabs is a reflection of what’s in my own brain, and a nearly-seamless extension of it.
Like every other web developer, I recently got a message from Firefox saying it needed to upgrade. (Because security researchers found yet another hole in Adobe Reader.) Despite the fact that I had over a dozen tabs open, I knew I wouldn’t have to worry about performing the upgrade, because Firefox would remember all my tabs and reopen them after restart. It’s basically a momentary hiccup in my workflow; I can start the upgrade and then use that 30-second break to refill my teacup or go to the bathroom. Come back, sit down, close the spare “You’ve just successfully upgraded Firefox” tab, and just keep working.
Compare that with Windows Update.