Apakah cloud computing?
What is Cloud Computing?Cloud computing is the access to computers and their functionality via the Internet or a local area network. Users of a cloud request this access from a set of web services that manage a pool of computing resources (i.e., machines, network, storage, operating systems, application development environments, application programs). When granted, a fraction of the resources in the pool is dedicated to the requesting user until he or she releases them.
It is called "cloud computing" because the user cannot actually see or specify the physical location and organization of the equipment hosting the resources they are ultimately allowed to use. That is, the resources are drawn from a "cloud" of resources when they are granted to a user and returned to the cloud when they are released.
A "cloud" is a set of machines and web services that implement cloud computing.
What is the Relationship Between Virtualization and Cloud Computing?Virtualization is the ability to run "virtual machines" on top of a "hypervisor." A virtual machine (VM) is a software implementation of a machine (i.e., a computer) that executes programs like a physical machine. Each VM includes its own kernel, operating system, supporting libraries and applications. A hypervisor provides a uniform abstraction of the underlying physical machine.
Multiple VMs can execute simultaneously on a single hypervisor. The decoupling of the VM from the underlying physical hardware allows the same VM to be started on different physical machines. Thus virtualization is seen as an enabler for cloud computing, allowing the cloud computing provider the necessary flexibility to move and allocate the computing resources requested by the user wherever the physical resources are available.
How Are Clouds Classified?Given the broad definition of the term "cloud," the current taxonomy differentiates clouds both in terms of cloud service offerings and cloud types. When categorizing cloud service offerings, we often refer to clouds in terms of "service style" depending on the portion of the software stack delivered as a service.
The most common service styles are referred to by the acronyms *Iaas, Paas, and Saas.
Cloud "types" (including public, private, and hybrid) refer to the nature of access and control with respect to use and provisioning of virtual and physical resources.