 Let's now start with the detailed understanding of the web of things from a conceptual perspective. Why did we need to transform or migrate from mere IOTs, which were perhaps good enough to WOT? Actually, we have some problem known as the IOT problem. IOT is a very good solution for a certain problem in a certain context, but when the context changes, or if there is a change in the underlying technology, then the entire IOT architecture is changed vertically. So it means that we need to have a continuous support for interoperable technologies at the four layers, while these layers continue to evolve. Now this becomes a challenge because creating the apps or the web-based interfaces that run atop these heterogeneous devices becomes very difficult because there is a continuous evolution of the devices, which are running certain softwares, are based on platforms with specific operating system releases, they are talking to different databases, each database is running a different environment, a different query language, and then if we are using middlewares, these middlewares are also allowing us to talk to certain interoperable or compatible protocols, but is it generalizable? It is not. So what is the solution? The solution is bringing everything to the web. So World Wide Web is a global platform that we have been seeing for internet-based services. It started off from web surfing or using the HTTP protocol for HTML web page access. So this is the classical protocol stack, it is the HTTP on top of TCP and on top of IP. Again like the typical client-server architecture as in web, we also can think about providing IoT services as in clients and servers. For discovering new set of IoT based services, we need to have a URL and DNS kind of mechanism. Now this technology, if it is interacting with things and is exposing the services of these things, abstracting away the underlying details, this is how the web of things becomes relevant to the IoT. So what possible services could we identify or could we demarcate in the services plane? So we will have web services as such. These are the services which would be directly accessible on the web. We can think about three tier architecture instead of a typical client-server, two tier architecture where we have the client talking to a web server and the web server is talking at the back end to a database server or directly to the IoT devices. Then we can think about the web of things service which is basically a service provided by an IoT through an adapter. So what happens is that web of things service is a service which maps the physical resources available and whatever functionality or service they are providing onto a certain service which is exposed by the worldwide web. So we can think about web of things services as basically the hardware connected web service. Then we can also have the mash-up service. So mashing up actually means taking the existing services which are more classical in the nature like IPTV, voice over IP, cloud services and integrating them with the WOT architecture. So mash-up services are also one of the possible variants. We can consolidate it again. Here we have the conceptual view of the IoT and WOT. We have the web-based services which are web service as such, web of IoT service and then we have the mash-up service. Now you see we have in this diagram specifically we have underlying architecture at the physical layer of constraint devices and full-fledged devices. These devices are exposing their hardware interfaces for configuration, for data access, for data manipulation, data read, write to their appropriate agents which are known as the brokers. So web of things brokers are basically having respective agents according to every technology. So these constraint devices need to have some kind of intermediary broker but for relatively high form factor devices like here we have the IP phone or complete laptop or smart television they can talk to the web services themselves. They can expose their services directly through certain software plugins and drivers of course. So the web of things broker allows the adaptation of different physical objects through their interfaces by having their respective agents.