What is cloud computing?

### What Cloud Computing is ? ### Cloud computing is a new buzzword in computing terms and it is associated with various definitions. In this book we focus on two definitions: the first is provided by the National Institute of Standards & Technology (NIST) and the second is provided by an EU study of the future directions of Clouds The main reasons for analyzing these definitions in particular are: # The good reputation of the organizations behind the definitions. For example, the EU study was edited by representatives of leading universities and industrial bodies such as Oracle, Google, Microsoft, and IBM. # We found thsse definitions to be unique, such that their combination provides the most important elements of Cloud as covered throughout this book. # NIST defines Cloud as a model for enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction. Although both definitions come from reputable organizations, they are not consistent. This is not to say that either of them is wrong, but they are incomplete. Both definitions reveal many important keywords reflecting Clouds capabilities; however, a careful analysis of these definitions shows they only have one keyword in common. The first definition uses â??rapidly provisioned and releasedâ?? while the second definition uses â??elastic execution.â?? These two keywords have the same objective. However, other keywords are not the same, for example â??minimal management effortâ?? as stated by the NIST definition is not stated anywhere in the EU definition. Similarly, the EU definition uses the keyword â??metered serviceâ?? which is again not stated anywhere in the NIST definition. read less