Real-time interactions happen as they happen. Timely ones, on the other hand, happen as you need them to happen. Some real-time interactions, like breaking news about an earthquake, can be timely. But not all timely interactions are real-time. I’d argue that most are not. And where the Fast Web is built around real-timedness, the Slow Web is built around timeliness.

Jack Cheng explaining The Slow Web. More on this subject later.