In its initial phase, all of the internet’s IP addresses were assigned to computers of one sort or another. Some of these were servers, and a growing number were clients that mostly consumed (but could sometimes modify) content on those servers.
As the internet — and in due course the worldwide web — developed, more kinds of (increasingly mobile) computing devices became connected, and web servers delivered ever richer content with which they could interact. Although this first internet/web revolution changed the world profoundly, the next disruptive development, in which the majority of internet traffic will be generated by ‘things’ rather than by human-operated computers, has the potential to change it even more.