Cloud computing is a collection of homogeneous or heterogeneous computer with a aim to fulfill singular or multiple tasks. Cloud Computing is a jargon term without a commonly accepted non-ambiguous scientific or technical definition. In science Cloud computing is a synonym for distributed computing over a network and means the ability to run a program on many connected computers at the same time.
Cloud computing is a model for enabling convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and
services) that can be rapidly provisioned and released with minimal management effort or
service provider interaction. This cloud model promotes availability and is composed of five
essential characteristics, three service models, and four deployment models.
—National Institute of Standards in Technology
- Location of Cloud
Cloud can be primarily classified based on location of the cloud and services offered through Cloud.
- Location of the cloud
- Private Cloud : In private cloud organization hosts cloud services within its own infrastructure which is usually the case when the organization has data which it wants to prevent from leaks. Usually organization maintains its own data center with virtualized environment and an automated user interface ,Backend is generally maintained by System Administrators or Architects.
2. Public Cloud: In Public cloud the computing infrastructure is hosted by the cloud vendor at the vendor’s premises.
3. Hybrid Cloud: Organization can use both private cloud and public cloud and interconnect them with vpn services or through MPLS line with encryption. Their emphasis is on to secure the data in private data and non confidential data can be kept in public cloud .
Cloud based services can be classified into
1. Infrastructure as a service (IaaS) :
Organization can directly configure Operating Systems , play with system parameters and can host n number of application on it , Its a virtualized environment provided to the organization with total control.
2. Platform as a Service (PaaS) :
It involves offering a development platform on the cloud. Platforms provided by different vendors are typically not compatible.
3. Software as a Service (Saas) :
Its a complete software offering provided to the client (organization) and can be use on pay-per-use basis.