Cloud computing refers to the use of networked infrastructure software and capacity to provide resources to users in an on-demand environment. With cloud computing, information is stored in centralized servers and cached temporarily on clients that can include desktop computers, notebooks, handhelds and other devices.
Cloud infrastructure can reside within the company’s datacenters (as internal clouds or on-premise solutions) or on external cloud computing resources (off-premise solutions available through service providers). It encompasses any subscription- based or pay-per-use service that extends existing IT capabilities.
Typically, Clouds utilize a set of virtualized computers that enable users to start and stop servers or use compute cycles only when needed (also referred to as utility computing). By design, cloud computing is scalable, flexible and elastic –offering IT staff a way to easily increase capacity or add additional capabilities on demand without investing in new and expensive infrastructure, training new personnel or licensing more software.
Different Flavours of Cloud Computing
Companies can leverage cloud computing for access to software, development platforms and physical hardware. These assets become virtualized and available as a service from the host:
SaaS – Software as a Service (Network-hosted application)
DaaS – Data as a Service (Customer queries against provider’s database)
PaaS– Platform as a Service (Network-hosted software development platform)
IaaS – Infrastructure as a Service (Provider hosts customer VMs or provides network storage)
IPMaaS – Identity and Policy Management as a Service (Provider manages identity and/or access control policy for customer)
NaaS – Network as a Service (Provider offers virtualized networks (e.g. VPNs))