Difference Between Public Cloud and Private Cloud
Cloud computing is a way of providing IT infrastructure to customers, it is not just a set of products to be implemented. For any service to be a cloud service, the following five criteria need to be fulfilled as follows:
- On-demand self-service: Decision of starting and stopping service depends on customers without direct interaction with providers.
- Broad Network Access: Service must be available to any device using any network.
- Resource Pooling: Provider creates a pool of resources and dynamically allocates them to customers.
- Rapid Elasticity: The services provided by the provider must be easily expandable and quick.
- Measured Services: Provider must measure the usage of service and charge it accordingly. Tracking usage is also helpful in improving services.
1. Public Cloud:
Computing in which service provider makes all resources public over the internet. It is connected to the public Internet. Service provider serves resources such as virtual machines, applications, storage, etc to the general public over the internet. It may be free of cost or with minimal pay-per-usage. It is available for public display, Google uses the cloud to run some of its applications like google docs, google drive or YouTube, etc.
It is the most common way of implementing cloud computing. The external cloud service provider owns, operates, and delivers it over the public network.
It is best for the companies which need an infrastructure to accommodate a large number of customers and work on projects which have diverse organizations i.e. research institutions and NGOs etc.
2. Private Cloud:
Computing in which service provider does not makes all resources public over the internet. It only supports connectivity over the private network. It has only authentic users and single-occupant architecture. Google back-end data of the applications like Google Drive, Google docs, YouTube, etc are not available to the public, these types of data and applications run on a private cloud.
The infrastructure and services are maintained and deployed over a private network; hardware and software are dedicated only to a private company i.e. members of the special entity.
It is best for the companies which need an infrastructure that has high performance, high security, and privacy due to its best adaptability and flexibility.
Below is a table of differences between Public Cloud and Private Cloud is as follows:
|Public Cloud||Private Cloud|
|Cloud Computing infrastructure is shared with the public by service providers over the internet. It supports multiple customers i.e, enterprises.||Cloud Computing infrastructure is shared with private organizations by service providers over the internet. It supports one enterprise.|
|Multi-Tenancy i.e, Data of many enterprises are stored in a shared environment but are isolated. Data is shared as per rule, permission, and security.||Single Tenancy i.e, Data of a single enterprise is stored.|
|Cloud service provider provides all the possible services and hardware as the user-base is the world. Different people and organizations may need different services and hardware. Services provided must be versatile.||Specific services and hardware as per the need of the enterprise are available in a private cloud.|
|It is hosted at the Service Provider site.||It is hosted at the Service Provider site or enterprise.|
|It is connected to the public internet.||It only supports connectivity over the private network.|
|Scalability is very high, and reliability is moderate.||Scalability is limited, and reliability is very high.|
|Cloud service provider manages the cloud and customers use them.||Managed and used by a single enterprise.|
|It is cheaper than the private cloud.||It is costlier than the public cloud.|
|Security matters and dependent on the service provider.||It gives a high class of security.|
|Performance is low to medium.||Performance is high.|
|It has shared servers.||It has dedicated servers.|
|Example: Amazon web service (AWS) and Google AppEngine etc.||Example: Microsoft KVM, HP, Red Hat & VMWare etc.|