Business in the Cloud
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6.5
Categories of Cloud Computing
Basically cloud computing consists of three simple categories: mere remotely
provided computing power, computers to run software and software itself (McAfee
&
Brynjolfsson, 2012, p. 56). An in-depth insight reveals even more, concrete
categories: Infrastructure-As-A-Service (IAAS), Platform-As-A-Service (PAAS) and
Software-As-A-Service (SAAS). A fourth category can also be defined by the grade
of human interaction involved in the cloud process: Human-As-A-Service (Lenk,
Klems, Jens, Tai, & Sandholm, pp. 2-4).
The common denominator for the three IT-related categories is that these services
are rented, not bought. Thus expenses for IT services are not investments anymore
but operating costs. Secondly the service providers are responsible for maintenance
(
planning, administration, backup, and debugging). Finally it is a simple task for a
company to expand the service level, if for example more storage space is needed
(
IAAS), more capacity for projects is demanded (PAAS), or more employees require
user access to SAAS applications (McAfee & Brynjolfsson, 2012, p. 56).
6.5.1
Infrastructure-As-A-Service (IAAS)
IAAS on the highest level of distinction refers to the provisioning of servers, storage
space, bandwidth and other fundamental computing resources by a service provider
(
Mell & Grance, 2011, p. 3). In most cases consumers of IAAS related services are
from the high-tech industry sector, which have IT know-how and demand access to
more computing power, but do not want to take care of maintenance and installation
(
McAfee & Brynjolfsson, 2012, p. 56). Furthermore a distinction on the lowest level
can be made into Physical Resource Set (PRS) and Virtual Resource Set (VRS).
PRS denotes proprietary physical hardware and VRS is based on virtualization
technologies, such as the Xen Cloud Platform for example (Lenk, Klems, Jens, Tai,
&
Sandholm, p. 2) & (Baun, 2010, p. 30).
