Cloud computing is a broad term used to describe a broad range of services. Cloud computing, often referred as cloud is the operation of storing, managing and processing data online rather than opting it on own devices and networks.
Cloud requires internet as medium of communication.
Cloud is a broad collection of services so everyone can use it according to their need. It also comes with types of environment suitable for every type of need. Environments defined is Public Cloud, Private cloud, Dedicated Servers and Hybrid Cloud. Based on the need of performance and budget, these environment serves their best serving their type.
Cloud Computing is often described as a stack, as a response to the broad range of services built on top of one another. It empowers end users to utilize parts of bulk resources which can be acquired quickly and easily upon request.
The diagram above depicts a cloud computing stack.
There are three distinct categories in cloud: Software as a Service (SaaS), Platform as a Service(PaaS) and Infrastructure as a Service (IaaS).
SaaS: SaaS is where a software which can be deployed on internet. With different licensing options like on demand, subscription based, pay-as-you-go or free to use, SaaS applications can be accessed using a web browser via internet. In short SaaS applications are designed for end-users. Online platforms like customer identity and access management, CRM etc are some pure SaaS based platforms mostly used by businesses.
PaaS: PaaS is a computing platform that allows the development of web applications quickly and easily, without buying and maintaining the software and infrastructure underneath it. PaaS enables development of web applications which requires special hardware and software requirements and saves users from installing hardware and software inhouse. Some successful examples of PaaS are, Windows Azure,, Force.com, Google App Engine etc.
IaaS: IaaS is a way of delivering Cloud Computing infrastructure. Clients instead of buying resources like servers, storage, network and operating inhouse, it buys those resources as a fully outsourced service on demand It comes with two sub-categories to choose from. Public Cloud and Private cloud. In a public cloud, a resource pool is shared and common for all the users but in a private cloud, a single pool of resource is dedicated.
Examples are Amazon Web Services (AWS), Cisco Metapod, Microsoft Azure, etc.
Though Iaas and PaaS seem to like a single entity but they are different at configuration and core level.
Understanding a cloud computing stack is necessary for everyone who is looking for opting cloud service for their needs.