 It's a known fact that Internet has grown tremendously over the last few years. In this module, we shall appreciate how Internet has grown, which are the contributing factors and of those which are the most dominating ones. The expansion of Internet can be qualified in terms of either the total number of hosts, the number of ISPs, which can also be understood as the number of networks, the number of applications which the users have started using over the Internet, and lastly, the resultant effect that shows itself as the total volume of traffic. Let's look at the change in the overall growth of Internet with respect to the type of users. It was mainly human-to-human interaction that was the primary focus of Internet, as we know in the form of email and other softwares. But as time passed, we have seen that human-to-machine communication started taking place. Somewhere around 2007, the trend has started gaining an exponential increase, and it also has an interesting aspect to it that the Internet of Things, the IoT, sometimes called machine-to-machine communication, involves communication between machines-to-machine per se. It means it does not necessarily involve humans in the loop. So it is quite likely that by 2019-2020, we'll be expecting that the most dominating contribution would be coming from the devices, especially the IOTs. There's another perspective of looking at how the Internet has grown in terms of the traffic usage. It is very important to understand that the traffic usage is contributed mainly from the number of applications and the types of applications. There you can see that of the dominant applications and softwares in 2009 and 2010, the real-time entertainment contributed the major part. But in 2010, there is a significant increase in peer-to-peer file sharing such as torrents. What it means is that in coming times, the peer-to-peer architecture of the Internet seems to be dominating the network applications part.