Cloud computing is the use of computing resources such as hardware and software, delivered as a service over the Internet. Users access Cloud’s applications using a web browser or a mobile application. On the other side, Cloud Servers store data.
Among its advantages, we can find that Cloud Computing reduces infrastructure costs. With this model, companies can focus on business projects and not on computing infrastructure. Another advantage is that companies can put their applications faster online with less maintenance, allowing better adaptation to changing business demands.
The change offered by cloud computing is that it allows increasing the number of network-based services, bringing benefits to both providers, and users. Providers offer a greater number of services in a fast and efficient way. User access services with transparency and immediacy, and with a pay-per-use model. This translates into cost savings.
The Cloud infrastructure has a high degree of automation, high adaptability to meet variable demand, advanced Virtualization and a flexible price made according to consumption.
The main purpose is to allow users to take advantage of new technologies, without requiring extensive knowledge of or experience with each of them. The cloud looks to cut costs, and help users to focus on their core business.
The key technologies in cloud computing are virtualization and autonomic computing. Virtualization abstracts the physical infrastructure, and makes it available as a “soft part” that is easy to use and manage, accelerating IT operations, cutting costs, and making a better use of the infrastructure. The autonomic computing automates the process users need to get access to resources on-demand.
Cloud computing adopts the concepts of service-oriented architecture (SOA), providing all resources as services, and using established standards and best practices of SOA, allowing easy global access to services of cloud and in a standardized way.
Cloud computing provides the tools and technologies for building data, complex applications with affordable prices compared to traditional computing techniques.
Providers offer cloud computing services according to several basic models:
Infrastructure as a Service.
Platform as a Service.
Software as a service.
Software as a Service
Software as a service corresponds to a complete application offered as a service. It has a single instance of the software running on the provider’s infrastructure, serving multiple organizations. In this case, users do not manage the cloud infrastructure and platform running the application, simplifying maintenance and support required.
The price is generally calculated as a fixed monthly or yearly per user, with the same scalable based on the number of users added or deleted at any time.
Among the best known examples have Salesforce.com, Google Apps, Microsoft Office 365.
Platform as a Service
In the platform as a service model, providers offer a complete computing platform, including operating system, runtime programming language, database, and Web server. Application developers develop and start their solutions on a cloud platform without the cost and complexity of buying and managing the hardware and software.
The best known examples are:
Google App Engine, which serves infrastructure applications Google.
Microsoft Windows Azure, a platform for the development and execution of applications in various languages and technologies like .NET, Java and PHP.
Infrastructure as a Service
In this model, the provider offers storage and compute capabilities as standardized services over the network.
Users must install operating system images and application software in the infrastructure offered. In this model, users are responsible for operating systems and application software maintenance. Cost is calculate based on the amount of resources allocated and consumed.
The best known example is Amazon Web Services, which offers computing and essential storage services.