Cloud Computing can be defined as the practice of using a network of remote servers hosted on the Internet to store, manage, and process data, rather than a local server or a personal computer. Companies offering these computing services are called cloud providers and typically charge for cloud computing services based on usage.
TYPES OF CLOUD SERVICES
Most cloud computing services fall into three broad categories:
1. Software as a service (Saas)
2. Platform as a service (PaaS)
3. Infrastructure as a service (IaaS)
4. Anything as a service (XaaS)
These are sometimes called the cloud computing stack, because they are build on top of one another. Knowing what they are and how they are different, makes it easier to accomplish your goals.
1. SOFTWARE AS A SERVICE
Software-as-a-Service (SaaS) is a way of delivering services and applications over the Internet. Instead of installing and maintaining software, we simply access it via the Internet, freeing ourselves from the complex software and hardware management.It removes the need to install and run applications on our own computers or in the data centers eliminating the expenses of hardware as well as software maintenance.
SaaS provides a complete software solution which you purchase on a pay-as-you-go basis from a cloud service provider.Most SaaS applications can be run directly from a web browser without any downloads or installations required.The SaaS applications are sometimes called Web-based software, on-demand software, or hosted software.
Advantages of SaaS :
1. Cost Effective : Pay only for what you use
2. Reduced time : Users can run most SaaS apps directly from their web browser without needing to download and install any software.This reduces the time spent in installation and configuration, and can reduce the issues that can get in the way of the software deployment.
3. Accessibility : We can Access app data from anywhere.
4. Automatic updates : Rather than purchasing new software, customers rely on a SaaS provider to automatically perform the updates.
5. Scalability : It allows the users to access the services and features on demand.
The various companies providing software as a service are Cloud9 Analytics, Salesforce.com, Cloud Switch, Microsoft Office 365, Eloqua, dropBox and Cloud Tran .
2. PLATFORM AS A SERVICE
PaaS is a category of cloud computing that provides a platform and environment to allow developers to build applications and services over the internet. PaaS services are hosted in the cloud and accessed by users simply via their web browser.
A PaaS provider hosts the hardware and software on its own infrastructure. As a result, PaaS frees users from having to install in-house hardware and software to develop or run a new application.Thus, the development and deployment of the application takes place independent of the hardware.
The consumer does not manage or control the underlying cloud infrastructure including network, servers, operating systems, or storage, but has control over the deployed applications and possibly configuration settings for the application-hosting environment.
Advantages of PaaS :
1. Simple and convenient for users : It provides much of the infrastructure and other IT services, which users can access anywhere via a web browser.
2. Cost Effective : It charges for the services provided on a per-use basis thus eliminating the expenses one may have for on-premises hardware and software.
3. Efficiently managing the lifecycle : It is designed to support the complete web application lifecycle: building, testing, deploying, managing and updating.
4. Efficiency : It allows for higher-level programming with reduced complexity thus, the overall development of the application can be more effective
The various companies providing Platform as a service are Amazon Web services, Salesforce, Windows Azure, Google App Engine, cloud Bess and IBM smart cloud.
3. INFRASTRUCTURE AS A SERVICE
Infrastructure as a service (IaaS) is a service model that delivers computer infrastructure on an outsourced basis to support various operations. Typically IaaS is a service where infrastructure is provided as an outsource to enterprises such as networking equipments, devices, database and web servers.
Infrastructure as a service (IaaS) is also known as Hardware as a service (HaaS).IaaS customers pay on a per-use basis, typically by the hour, week or month. Some providers also charge customers based on the amount of virtual machine space they use.
It simply provides the underlying operating systems, security, networking, and servers for developing such applications, services, and for deploying development tools, databases, etc.
Advantages of IaaS :
1. Cost Effective : Eliminates capital expense and reduces ongoing cost and IaaS customers pay on a per use basis, typically by the hour, week or month.
2. Website hosting : Running websites using IaaS can be less expensive than traditional web hosting.
3. Security : The IaaS Cloud Provider may provide better security than your existing software.
4. Maintainence : There is no need to manage the underlying data center or the introduction of new releases of the development or underlying software. This is all handled by the IaaS Cloud Provider.
The various companies providing Infrastructure as a service are Amazon web services, Bluestack, IBM, Openstack, Rackspace and Vmware.
4. Anything AS A SERVICE
Most of the cloud service providers now a days offer anything as a service that is a compilation of all of the above services including some additional services.
Advantages of XaaS :
All of the above advantages