Based on the question given, we do not agree that Cloud Computing and Grid Computing is the same. Cloud Computing and Grid Computing are not technology, they are consider as a concepts which often implements in computing industry nowadays. Cloud Computing and Grid Computing have the same purpose, that is to hidden the complexity of the system process, so users only need to use and without the need to understand how the system works. Therefore, many people often misunderstanding Cloud Computing and Grid Computing are the exactly same things, but actually they are not same in all cases.
Actually the Cloud Computing is overlaps from the Grid Computing, Distributed Computing, Utility Computing, Services Computing in general. The development of Cloud Computing is evolved from the Grid Computing. The Cloud Computing and Grid Computing both distributed computing paradigm but the Cloud Computing is a business model, it is more used in business world, such as Amazon, Google, and also Microsoft, they need the real commercial large scale system to manage and store the data in large storage which containing hundreds of thousands computers to manage their resources. While, for Grid Computing is more used in scientific community, such as drug development field.
As Cloud Computing are evolving from Grid Computing, there are obviously does have many similarities. First, both Cloud Computing and Grid Computing are scalable, that means the system is able to handle increase in workload, or to improve performance. For example, when the application instances are load in balancing, network bandwidth and CPU (central processing unit) will be directed on demand. This indicates Cloud Computing and Grid Computing will cause fluctuations in storage capacity, due to the number of users, instances and total numbers of data transmit in a specific time.
Besides that, both Cloud Computing and Grid Computing are employing multi-tenancy architectures and multi-tasking. Multi-tenancy is refers to the circumstances where multiple clients are able to serve by only one instance of software and multi-tasking is refers to when there are more than one processes share the processing resources. That means both Cloud and Grid Computing allow many users to carry out different tasks and can access one or more application instances.
Another similarity between Grid Computing and Cloud Computing is both networks will abstract the processing task. This feature will hide the complexity of processes execution within a system so that user doesn't need the knowledge of internal process execution within distribute system. Simple interface is display to user so that they can interact easily. This features cause the system become more user-friendly.
Although Cloud Computing is evolved from Grid Computing and have many similarities, but we still disagree they are the same things. This is because Cloud Computing and Grid Computing still exists a lot of differences. In term of resources provision, there is the different between Grid Computing and Cloud Computing. For Grid Computing, there is some limit in resources allocation, the user/virtual organization only can get the resources as they are agreed the contract between the allocator/ admin domain. Compared to Cloud Computing, it's does not have restriction or limitation on resources allocation, as far as users pay for resources they want. Besides that, Cloud Computing is taking this advantage over Grid Computing because of Cloud Computing can made provision on demand resources but Grid Computing can only choose either to turn on or turn off the computing resources and this will result on over-provisioning of resources. Cloud Computing can help to knockout over-provisioning resources when use with utility pricing and can suit with demands of millions of users.
One of the differences are whereas Grid Computing will be use in environments where user make few/less but large allocation requests. For example, a laboratory which used Grid Computing may have 2000 node cluster and users of the laboratory make allocations for whole 2000, or 1000, etc. Hence, only a small amount of these allocations can be serviced at one time and the other have to wait until the resources are released. However, Cloud Computing is concerning the many of small allocation requests. For example, by default, each Amazon EC2 account has been limited to 20 servers and plenty of users can allocate up to 20 servers from thousands of servers at Amazon. These allocations are concurrent/real-time and actually there do not have any provision for queue until other resources are released.
One of the reason that many people often misunderstanding that Cloud Computing and Grid Computing is the same is that, both use shared resource and visualization to implement task but they are differ conceptually. In fact, Cloud Computing are more focus on which services provided can be use on the internet but not on local computers whereas Grid Computing involves sharing of tasks over multiple computers. For example, in Cloud Computing, the data is store in the "Cloud", which allows user to access, means that it is accessible anywhere, and data can be shared with others. So, we can say that the Cloud Computing provides services on demands through Internet and where it is shared information, resources, software to users. For Grid Computing, it's collected computer resources to perform multiple tasks that execute in parallel to accomplish computation goal and solving computation problem.
In term of architecture, both Grid Computing and Cloud Computing are different. Grid Computing has five layers of architecture which each of the layer provided different protocol and services. The five layers are shown as the Figure (a). While for the Cloud Computing, its only has 4 layers architecture that is fabric layer, unified resource layer, platform layer, and application layer which is shown in Figure (b).
Figure (a): Grid Architecture
Figure (b): Cloud Architecture
