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))