In the simplest terms, cloud computing means storing and accessing data and programs over the Internet instead of your computer’s hard drive. The cloud is just a metaphor for the Internet. Cloud computing, often referred to as simply “the cloud,” is the delivery of on-demand computing resources — everything from applications to data centers — over the internet on a pay-for-use basis.
Based on a cloud location, we can classify cloud as:
Based on a service that the cloud is offering, we are speaking of either:
- Private Cloud
- IaaS (Infrastructure-as-a-Service)
- PaaS (Platform-as-a-Service)
- SaaS (Software-as-a-Service)
Private Cloud is great where you full control over your data & complete flexibility to configure your cloud exactly how you want it to work. You control all the hardware, network, environment, etc to do with your cloud setup. This ensures you don’t rely on 3rd parties with your data, if this is something you would prefer not to do. On Premise could be the most expensive options, as you don’t get to take advantage of economies of scale that a cloud provider can take advantage of. You may need to buy a bunch of extra capacity you won’t be using, and you will need the expertise in house to manage the cloud.
Some examples of the popular Private Cloud are:
Infrastructure as a Service is (IaaS) known as Cloud infrastructure services, , Infrastructure as a Service is renting the infrastructure to run your own application and OS. The users get the IT infrastructure which includes storage, servers, virtual machines, networks from the service provide. are self-service models for accessing, monitoring, and managing remote datacenter infrastructures, such as compute (virtualized or bare metal), storage, networking, and networking services (e.g. firewalls). Instead of having to purchase hardware outright, users can purchase IaaS based on consumption, similar to electricity or other utility billing.
Some examples of the popular IaaS providers are:
- Amazon EC2
- Windows Azure
- Google Compute Engine.
Platform as a Service (PaaS), are used for applications, and other development, while providing cloud components to software. PaaS is great if you have an application developed for the specific PaaS platform, and means you don’t have to worry about hardware, network, or managing the OS, and underlying software to run your application. You can focus on the development of your application and easily scale as you require additional resources. These kind of cloud services provide environments for various purposes like development, testing, etc. It helps developers create applications
PaaS services are usually billed as an incremental cost on top of the IaaS monthly charges. For example, there may be a small monthly fee for the use of a load balancer or a database backup service.
Some examples of the popular PaaS providers are:
- AWS Elastic Beanstalk
- Windows Azure
- Google App Engine
SaaS (Software as a service) – This service provides the complete product applications to the users hence eliminating the needs of the underlying services where the user need not to worry about hardware and platforms for the generation of the final product. Cloud application services, SaaS, represent the largest cloud market and are still growing quickly. Software as a service is a term used to describe a storage model where a business or organization persons rents or leases storage space from a third party provider. The data is transferred from the person and to the services provider via internet and the person would then access their stored data using software provided by the storage provider. Most SaaS applications can be run directly from a web browser without any downloads or installations required, although some require plugins.
Some examples of the popular SaaS providers are:
- Google Apps
- Microsoft Office 365.