It was George Favaloro and Sean O’Sullivan, managers of Compaq Computer, who first used the expression “Cloud Computing” in 1996, and since then, the term has become so popular that I already meet primary school children who know, for example, that Siri does not live inside iPads but much further away, “in the cloud”.
However, as technology develops, a hodgepodge of terms and acronyms appear that are difficult for non-technologists to understand. So the intention of this post is to try to explain these terms in a simple way in order to explain the details of the very general concept of “the cloud”.
Cloud terms glossary
- API: “Application Programming Interface”. It is the standard mechanism for communication between applications. It is an interface that allows different applications to request data and deliver it in a predefined format and according to specific rules.
- Cloud Computing: Here I borrow the definition given by Salesforce, which in 1999 was the first company to market enterprise services from the cloud: “Cloud computing is a technology that enables remote access to software, file storage and data processing over the Internet, thus providing an alternative to running on a personal computer or local server. In the cloud model, there is no need to install applications locally on computers. Cloud computing offers individuals and businesses the capability of a well-maintained, secure, easily accessible, on-demand pool of computing resources”.
- Hybrid Cloud: Cloud deployment model that combines the dedicated computing resources of a private cloud for critical data and applications with the shared resources of a public cloud to meet peak demand.
- Private Cloud: In this case, the computing resources and environment are for the exclusive use of an organisation. It is comparable to having one’s own data centre within an organisation, but with the advantages of delegating its management and dimensioning it on demand thanks to virtualisation.
- Public Cloud: A deployment model in which an internet service provider offers computing resources over the internet on an infrastructure shared by several organisations on a pay-per-use basis.
- Cluster: It is a collection of servers that are connected to each other through a network, and which behaves like a single server in many respects.
- Colocation o Housing: Service offered by companies that provide data centres in advanced and secure facilities to host the technology platforms owned by their customers. These facilities offer high quality services and connectivity.
- DPC: Data Processing Centres. These are the physical locations where all the electronic equipment necessary for the processing and storage of a company’s information is located.
- Hypervisor: A hypervisor, also known as a virtual machine monitor (VMM), is software that creates and runs virtual machines and isolates the operating system and hypervisor resources from the virtual machines, allowing them to be created and managed. When the physical hardware system is used as the hypervisor, it is referred to as a ‘host’, and the multiple virtual machines that use its resources are referred to as ‘guests’. The hypervisor uses resources, such as CPU, memory and storage, as a pool of media that can be easily redistributed among its guests.
- IaaS: Infrastructure as a Service. With IaaS, a virtualisation-based solution is available where the customer pays for resource consumption such as disk space used, CPU time, database space or data transfer.
- Latency: Or network latency, the time it takes for a data packet to be transferred between a server and a user over a network.
- Virtual Machine: A virtual machine (VM) is a virtual environment created on physical hardware using a hypervisor that has its own operating system, CPU, memory, network interface and storage.
- Metacloud: Tools for the management and administration of multiple clouds, also managing resources in the cloud and exposing APIs to applications.
- Multicloud: A cloud deployment model in which services from multiple cloud providers are combined to take advantage of the specific benefits of each provider.
- On-demand: Equivalent to “on-demand”. In the technology field, it is used to express the flexibility of cloud products, based on a pay-per-use model in which the provider makes all its resources available to the customer on demand so that the customer can respond to peaks and troughs in demand.
- On-premises: This is the traditional licensing scheme, i.e. the company acquires the licences that grant it the right to use the provider’s systems, integrates them into its own installations and maintains its data within its own infrastructure.
- Open Source: Free software should not be confused with freeware because free software does not have to be free. The source code of Open Source is “Open Source” and programs licensed under the GPL (“General Public License”), once acquired, can be freely used, copied, modified and redistributed.
- PaaS or Platform as a Service is a cloud computing service model that provides a ready-to-use development environment over the Internet in which developers can develop, manage, distribute and test their software applications.
- PUE: Power Usage Effectiveness is the value that results from dividing the total amount of energy used by a data centre facility by the energy supplied to the data centre’s IT equipment. Items such as lighting or cooling fall into the category of energy used by a data centre facility. The closer the PUE value is to 1, the more efficient the data centre is.
- Disaster Recovery: or Disaster Recovery is a method of recovering data and functionality after a system outage due to a disaster, natural or human-induceds.
- SaaS or Software as a Service is a cloud computing service model that consists of distributing software applications hosted in the cloud to users via the Internet through a subscription or purchase payment model, while maintaining the privacy of their data and the personalisation of the application.
- Bare-metal server: A bare-metal server is a physical server with a single tenant, i.e. for the exclusive use of the client that contracts it and which is not shared with other organisations or users.
- SLA: Service Level Agreement. This is a protocol, usually set out in a legal document, whereby a company that provides a service to another company undertakes to do so under certain service conditions.
- Oversubscription. Oversubscription of resources occurs when a shared hosting or Public Cloud provider offers a number of computing resources in excess of the available capacity, on the theory that customers do not use 100% of the resources offered.
- VPN: AVirtual Private Networkis a network that creates a private, encrypted and secure connection between two points over the Internet. VPN communication tunnels allow encrypted and secure traffic to be sent and allow company employees to access the information they need from their company, even if it is private.