Public Cloud vs Private Cloud vs Hybrid
Clouds are typically defined according to three types: private, public and hybrid
Public clouds:
Also known as a shared cloud, such services are provided "as a service" over the Internet with little or no control over the underlying technology infrastructure. This cloud is appealing to many decision-makers as it reduces complexity and long lead times in testing and deploying new products. It is generally cheaper, too.
Private clouds:
Also called an internal cloud or enterprise cloud, this also offers activities and functions "as a service" but is deployed over a company intranet or hosted datacenter. This is private product for a company or organization offering advance security and highly available or fault tolerant solutions not possible in a public cloud. In this scenario, the private cloud owner shares few, if any, resources with other organizations. Hence, multi-tenancy is not an issue.
Hybrid clouds:
This is an integrated approach, combining the power of both public and private clouds. Customized rules and policies govern areas such as security and the underlying infrastructure. In this scenario, activities and tasks are allocated to internal or external clouds as required.
MOST COMMON SERVICES
While clouds may be private or public, they are also further differentiated at the service-type level. There are broadly speaking three types of dominant services:
Software-as-a-Service (SaaS)
SaaS refers to an end user accessing a remote product or e-commerce service over the Internet. These could include an outsourced email serice such as in available through Microsoft Office 365 or Pay Per Cloud, or a data center offered by Amazon Web Services.
Platform-as-a-Service (PaaS)
PaaS is geared towards developers who wish to deploy applications in the cloud and don't want to get involved with the server infrastructure. Microsoft Azure is just one example of this service.
Infrastructure-as-a-Service (IaaS)
The final version, IaaS, allows developers maximum interaction with the underlying server infrastructure including, but not limited to, deploying back-office applications on that remote environment.
MOST ESTABLISHED SERVER VIRTUALIZATION TECHNOLOGIES
Arguably, the defining moment for virtualization architecture servers occurred when VMware released its first server products in 2001. VMware dominated the market until Xen hypervisors made its first appearance in 2006 followed by Microsoft's Hyper-V in 2008.
Typically, web hosts such as Virtual Internet use these solutions to virtualize their applications from their x86 Server hardware or software systems thus reducing cost and minimizing wasted resources when delivering server capacity that applications need.
These virtualization solutions leverage:
- Hypervisors to create virtual machines
- Shared Operating virtualization technologies
- Server virtualization administrative & embedded management
VMware and Hyper-V dominate the cloud landscape.