1. Cloud Computing Concept&nature Cloud computing refers to the applications delivered as services over the Internet and the hardware, and systems software in the data centers that provide those services. The data center hardware and software what we will call a Cloud... It's called Cloud computing because the data and applications exist on a "cloud" of Web servers

2. Cloud Computing To simplify the concept, Cloud computing can be defined as simply the sharing and use of applications and resources of a network environment to get work done without concern about ownership and management of the network's resources and applications

4. Cloud Computing Example for cloud computing Web-based email services such as Hotmail or Yahoo were among the earliest popular forms of cloud computing. If you use Facebook to interact with friends, Flickr to store photos, or Googlemail to send email, you're already storing your data in the cloud and using a service whose behind-the- scenes magic is cloud-based too,google map.

5. Key Characteristics Cloud computing is cost-effective. Here, cost is greatly reduced as initial expense and recurring expenses are much lower than traditional computing. Maintenance cost is reduced as a third party maintains everything from running the cloud to storing data. In cloud computing, security is tremendously improved because of a superior technology security system, which is now easily available and affordable. In a nutshell, cloud computing means getting the best performing system with the best value for money.

6. Virtualization technology Virtualization technology works to handle on how the image of the operating system, middleware, and application procreated and allocated to a physical machine or part of the server stack away. The virtualization technology can also help reuse licenses of operating systems, middleware, or software applications, once a subscriber releases their service from the Cloud Computing platform.

7. Virtualization technology Cloud Architecture runs on a very important assumption, which is mostly true. The assumption is that the demand for resources is not always consistent from client to cloud. Because of this reason the servers of cloud are unable to run at their full capacity. To avoid this scenario, server virtualization technique is applied. In sever virtualization, all physical servers are virtualized and they run multiple servers with either same or different application. As one physical server acts as multiple physical servers, it curtails the need for more physical machines

8. Service Oriented Architecture (SOA). A service oriented architecture is essentially a collection of services. These services communicate with each other. The communication can involve either simple data passing or it could involve two or more services coordinating some activity. Some means of connecting services to each other is needed. The evolution of a system or software architecture is now moving towards services oriented.

9. Service Oriented Architecture (SOA). Giant company such as Google, Microsoft, Sun or even Amazon have this capability provide software services instead of selling the software directly to user. reusability, extensibility, and flexibility. These entire characteristic is a fundamentals need for company that are looking for reducing cost and opt to rent instead of purchase.

10. Cloud Computing security Security of confidential data (e.g., SSN or Credit Card Numbers) is a very important area of concern as it can make way for very big problems if unauthorized users get access to it. in cloud computing it is very important to be aware of data administrators and their extent of data access rights. sometimes the network utilizes resources from another country or they might not be fully protected

12. Hawraa abed al-kaream Third stage