Cloud Systems and Technologies

- Cloud Servers

A cloud server is a pooled, centralized server resource that is hosted and delivered over a network (usually the Internet) and accessed on-demand by multiple users. Cloud servers can perform all the same functions as traditional physical servers, providing processing power, storage, and applications. 

Cloud servers can be located anywhere in the world and provide services remotely through a cloud computing environment. In contrast, traditional dedicated server hardware is often set up locally for exclusive use by one organization.

- The Core of Cloud Computing - The Internet

When the Internet was in its infancy the word 'cloud' was used as a metaphor to describe how the complex telephone networks connected. Cloud is a model of computing where servers, networks, storage, development tools, and even applications (apps) are enabled through the Internet.

Cloud computing is 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. As cloud computing becomes mainstream, organizations are now moving toward adopting it into the in-house processes. As such, almost all industries are witnessing an increase in the use of cloud-based platforms and services. 

Cloud technology is helping businesses and people weather the ongoing storm caused by the global pandemic (COVID-19). As companies adapt to become elastic digital workplaces and deal with an increase in online demand and remote working, they're migrating their services and data to the cloud. For businesses that have already begun the move to cloud computing, they're accelerating a transformation that will lead the way forward in the years to come.

- Classifications of Cloud Computing

Cloud computing is the delivery of computing services like servers, storages and more over the Internet. The companies that offer these computing services are called cloud providers. They charge for cloud computing services based on usage.

Cloud computing is usually classified on the basis of location, or on the service that the cloud is offering. Based on a cloud location, we can classify cloud as: Public, Private, Hybrid, and Community Cloud. Based on a service that the cloud is offering, we classify as: IaaS (Infrastructure-as-a-Service), PaaS(Platform-as-a-Service), SaaS(Software-as-a-Service), or, Storage, Database, Information, Process, Application, Integration, Security, Management, Testing-as-a-service.

Although you do not realize you are probably using cloud computing right now, most of us use an online service to send email, edit documents, watch movies, etc. It is likely that cloud computing is making it all possible behind the scenes. 

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- Five Key Characteristics of A Cloud Computing

There are five key characteristics of a cloud computing environment, as defined by the National Institute of Standards and Technology (NIST): internet access, measured services, on-demand self-service, shared resource pooling, and rapid elasticity. 

• Internet Access: With a public cloud environment, users "plug into" the data and applications via an internet connection giving anytime, anywhere access. 
• Measured Service: Cloud is often pay-as-you-go, where you only pay for what you use. Think about how a utility company meters how much water, electricity, or gas is used and charges based on consumption. The cloud is the same. 
• On-Demand Self-Service: Services can be requested and provisioned quickly, without the need for manual setup and configuration. 
• Shared Resource Pooling: Cloud often uses the multi-tenancy model. This means a single application is shared among several users. So, rather than creating a copy of the application for each user, several users, or "tenants" can configure the application to their specific needs. 
• Rapid Elasticity: Cloud platforms are elastic. An organization can scale its resource usage levels up or down quickly and easily as needs change.

- The Core of Cloud Computing Technologies

There are two key elements at the core of cloud computing technology, which are: SOA (Service Oriented Architecture) and cloud virtualization, which are described in further detail below:

• SOA or Service Oriented Architecture defines a way to make software components reusable and interoperable through service interfaces. Services use common interface standards and architectural patterns so they can be quickly integrated into new applications. This removes the task of previously reinventing or duplicating existing functionality or application developers who must know how to connect to existing functionality or provide interoperability with existing functionality.
• Virtualization is the basic technology that supports cloud computing. Virtualization is software that manipulates hardware, while cloud computing refers to the services that result from this manipulation. It is impossible to have cloud computing without virtualization. Cloud computing is based on a virtualization technology where software called a hypervisor runs on a real machine and creates a virtual operating system on that specific machine. These virtual machines can run any application on them. Therefore, end users can easily use cloud services.