Cloud Computing is the use of the remote servers on the web to store, manage and process data rather than storing on the local server. The data can be managed using databases and it can be processed on the remote server. There are two cloud models:
Infrastructure as a Service (IaaS) provides virtualised computing resources over the internet and it removes the problem of depending on the physical machines.
Platform as a Service (PaaS) gives the ability to the customer to deploy customer created application using programming languages provided by the cloud provider and also there is no control over the underlying architecture including operating systems, storage, servers.
Software as a Service (SaaS) leases applications or softwares which are owned by them to its client. For example: salesforce.com provides CRM on a cloud infrastructure to its client and charges them for it, but the software is owned by salesforce.com only.
Public Cloud: It is a cloud deployment model where service provider makes resources available to the public via the internet and their computing resources are owned and operated by a provider. It relies on a virtualised environment to provide an extension of a company’s IT infrastructure, allowing that company to host certain aspects of its infrastructure and services on virtual servers that are offsite and owned by a third party. It helps in lowering equipment purchase costs and its maintenance costs.
Hybrid Cloud: It is an infrastructure that includes bridges between one private cloud managed by the user and at least one public cloud managed by a third party and this kind of environment allows organisations to benefit from the advantages of both types of cloud platforms and choose which cloud to use based on specific data needs.
Private Cloud: It is an environment that runs on a dedicated infrastructure and focuses on scalability, improved resource utilisation and self-service capabilities. It also provides strong control and security over its apps, data and systems while offering cloud-like agility.
AWS is a subsidiary of Amazon.com which provides on-demand cloud computing platforms on a pay and go basis with the freemium of 12 months. It was launched in 2006 when no company had the cloud computing business model and now approximately 70% of the businesses are running on AWS. There are various organisations using cloud services such as Kellogg's, Netflix, GE, Adobe, Amazon, Airbnb.
AWS helps a lot of startups in setting up their infrastructure such as if an individual or company wants to launch an application and make it available to the world, some servers would be required and the application will be up and running. Supposedly, if the application doesn't get success as planned and the benchmarked number of users do not visit the application or there are huge number of customers which the server is not able to handle, what will happen to your monthly plan for the servers? You would require to invest more money in the servers which will incur a heavy amount of cost for infrastructure. That's where AWS come into picture.
AWS charges only the amount of time you use, for example: if you use 5 hours of AWS, you will be charged for that much time and not for the whole day. The maintenance of the servers is also handled by them only. If you are using the manual server methodology then a separate maintenance team will be required to make sure the servers are running well in background.