Cloud Computing

Definition

Cloud Computing. It is a computing capability that provides convenient and on-demand network access to a shared pool of configurable computing resources. These resources can be rapidly provisioned and released with minimal management effort or vendor interaction.

Cloud computing is Internet-based computing, whereby shared resources, software and information are provided to computers and other devices on-demand. It is a "paradigm shift" following the shift from mainframe to client–server in the early 1980s.

Cloud computing describes a new consumption and delivery model for IT services based on the Internet, and it typically involves the provision of dynamically scalable and often virtualised resources as a service over the Internet. It is a by-product and consequence of the ease-of-access to remote computing sites provided by the Internet.

Characteristics

Cloud computing has six essential characteristics:

• pay-per-use
• self-service
• broad network access
• resource pooling
• rapid elasticity, and
• measured service.

Modes

Cloud computing can be public, private, or hybrid. In general terms, cloud computing enables three possible modes:

• Infrastructure as a Service (IaaS)
• Platform as a Service (PaaS), and
• Software as a Service (SaaS).

Issues and Challenges

The public mode of cloud computing raises (in principle) issues of Data Privacy as potentially sensitive Personal Data are transferred over networks and processed in third party infrastructure.