 We have heard a lot about different kinds of service offerings or the service categories which could be there on cloud. We know mobile clouds. We know software service over the cloud. We know IoT over the cloud. So what are these and essentially in terms of technical specifications, how could these be offered or could be used over the cloud? For that we will have to refer to the 2012 document by the ITUT. It was a technical report by the focus group on cloud computing, one of the initial documents. It's a very good reference because that helps us to get an insight into the service categories. We start off with the infrastructure as a service. What is that? The consumer could subscribe to very basic computing and networking resources like processing, storage, the network connectivity, for example, VLAN or some rules like firewall rules or load balancing mechanisms. Even the application accelerator services which help an application to run faster by understanding how the application is running and then assigning the resources correspondingly. So this helps the consumer to run an arbitrary application on the cloud infrastructure. So the cloud is acting more like bare metal. Then we have software as a service. As the name suggests, the provider has some specific applications. For example, you might have heard of RASTA app which is provided by the motorway police and the city traffic police. So this is an application which is provided by the service provider. Now the cloud is going to run this service provided by the provider for the consumer in the cloud infrastructure. So it means that the mobile phone or the laptop smartphone would be least burdened with this app because the app is now being run into the cloud. Then we have communication as a service. Essentially communication could have many forms like SMS, short message service, instant messaging, voice over IP and interactive video two-way or entire video conferencing. If a certain cloud is providing that, it's known as communication as a service. Then we have the platform as a service. The platform is actually one level above in terms of abstraction than the infrastructure as a service. So what happens is the user is allowed to create applications of their own or acquire applications which are available onto cloud by using the programming languages, the runtime environment for interface design, creating and accessing database and then the storage of this particular app on the cloud and testing its service. So we can think about using platform as a service for modern day environments where the freelance developers are banking onto this platform as a service significantly more. Then we have network as a service. We all know that cloud is essentially devices connected together, so it's a network in itself. But is that network connectivity being offered similar to the communication as a service? Well, if that happens, it means that the user, the consumer CSC, is now being allowed to access transport services or inter-cloud connectivity. This actually has a disclaimer. That is, depending upon the visibility that the cloud service provider or the cloud service network wishes to give to the cloud service consumer, only that much network would be accessible and usable by the consumer. So this could include the extending the virtual private network services between the home office, head office and the remote sites and then having bandwidth on demand. This is a summarized view of the cloud services which are mapped onto cloud service categories. Some of the very basic examples are the desktop as a service. The desktop could use infrastructure as a service because in your desktop all you need is essentially a motherboard with a processor, with a LAN card, with some memory and that's it. That's about it. Then we have service delivery platform as a service. Well, this is now going to invoke the communication as a service and software as a service as well. So this could include hardware that is desktop as a service in addition an operating system running on the top. Then cloud communication center that is more like a call center over a cloud. Then VPN, virtual private network where a tunnel is opened between multiple endpoints over the internet. And then bandwidth on demand again is an example of network as a service. Again, this document is a reference. It's an amazing report which is being cited by ITUT again and again for their latest recommendations in the cloud.