In this post we want to collect the most common terms in cloud computing; from basic concepts such as the cloud service models and types to more specialized concepts related to cloud computing. Let’s start from the beginning…
What’s cloud computing?
Cloud computing is a computing resources and services distribution model —from applications to storage resources, networking and processing capabilities— over the Internet, on demand and on a pay per use model. So, in cloud computing, cloud providers or ISPs are responsible for managing computing resources and applications, depending on the cloud service model they offer. While users only pay for the services they use and scale whenever they need.
Although the term “cloud computing” started to gain popularity at the beginning of the 21st century, the concept “computing as a service” was already known as “virtualization” before.
Cloud computing glossary
Bandwidth is the maximum data transfer capability of a network or Internet connection; that is to say, the amount of data that can be sent through a connection at the same time. Bandwidth is usually measured in Megabits per second (Mbps).
A Bare-metal server is a physical server with a single tenant; that is to say, a physical server of exclusive use of the client who rents it, which isn’t shared with other organizations or users.
A CDN or Content Delivery Network is a network of servers and data centers which are geographically distributed in order to improve availability and performance by placing content copies in a cache closer to end users.
A cluster is a group of servers that are connected with each other over a network, and which acts as a single server in many aspects.
A CPU or Central Processing Unit is an electronic circuit inside a computer that executes the specific instructions of every software program via basic arithmetic, logic, control and input/output operations. A CPU can be composed of several “cores”, which are the different processing cores, so that modern processors are able to perform several tasks at the same time. Additionally, every core can be able to process several threads simultaneously (Intel’s technology called “Hyperthreading”).
A data center or Internet data center (IDC) is a physical location where an organization or Internet service provider’s necessary computing resources are gathered. More details about what’s a data center.
Disaster Recovery (DR) is a procedure to recover data and functionalities after a system has been disrupted because of a disaster — either natural or caused by humans. More details about what’s a Disaster Recovery plan and how to build one.
A hot migration is the process of moving a system or virtual machine from one server or data center to another without turning it off or disrupting its availability.
The Hybrid Cloud is a cloud computing deployment model that combines the dedicated resources of a Private Cloud for mission-critical applications and data with shared resources in a Public Cloud for handling unusual traffic peaks. More details about the Hybrid Cloud.
A hypervisor is a layer of virtualization software that allows to create and run several virtual machines within a single server, as well as different operating systems. It is in charge of separating the resources of the virtual machine from the hardware system and of distributing them properly. It is also known as virtual machine monitor (VMM).
IaaS or Infrastructure as a Service is a cloud computing service model that consists of providing and managing computing resources — such as servers, storage or networks — over the Internet. More details about what’s IaaS and its advantages.
Internet Exchange Point
An Internet Exchange Point (IXP) is a physical infrastructure that makes traffic exchange easier among networks for ISPs. IXPs allow networks to interconnect directly via their infrastructure, instead of through third-party networks. More details about what’s an IXP and its advantages.
IOPS or Input/Output Operations Per Second is a unit of measurement which is used for indicating the performance of storage computing devices and network storage volumes. It’s an important information since the greater the IOPS capacity is, the greater the performance for writing or reading data is.
An ISP or Internet Service Provider is a provider of Internet services such as cloud solutions, network storage or networking.
The latency or network latency is the time it takes to transfer a packet between a server and an user through a network.
A legacy system is an old or out-of-date system, technology or software application that continues to be used by an organization because it isn’t possible to replace it or update it easily — or just because the organization doesn’t wish to do so. More details about what’s a legacy system.
The Multicloud is a cloud computing deployment model which combines cloud services from several public and private cloud providers, in order to leverage the specific advantages of multiple providers.
A network equipment or network hardware is an electronic device that allows data transfer and interaction among devices within a computers or servers network.
Network storage is a technology that allows to share storage capacities among servers or computers through a network and remotely, thanks to a direct connection or protocols such as NFS, iSCI, etc.
The concept “noisy neighbor” is an effect that happens in cloud environments and infrastructures that are shared among several customers. It occurs when the activity of a virtual machine (VM) deteriorates the performance of another VM within the same physical infrastructure. This effect is usually caused by the oversubscription of resources.
The oversubscription of resources happens when a shared hosting or Public Cloud provider offers a series of computing resources that exceeds the available capacity, because they assume customers don’t use all the resources offered. More details about what’s the oversubscription of resources.
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. More details about PaaS or Platform as a Service.
The Private Cloud is a cloud computing deployment model in which the computing resources and environment are of exclusive use by an organization. A Private Cloud is comparable to owning a data center in a company, but with the benefits of delegating its management and scaling on demand thanks to virtualization. More details about the private cloud and its advantages.
The Public Cloud is a cloud computing deployment model in which an ISP offers computing resources over the Internet within an infrastructure which is shared among several organizations, based on a pay per use model. More details about the Public Cloud.
The PUE ratio (Power Usage Effectiveness) is used for measuring data centers’ energy efficiency. The PUE is the value derived from dividing the total amount of energy used by a data center facility by the energy delivered to the data center’s computing equipment. More details about the PUE ratio.
RAM memory or Random-Access Memory is the main memory of servers and personal devices. It temporarily stores the data of the programs in use during a session.
SaaS or Software as a Service is a cloud computing service model that consists of distributing cloud-hosted software applications to users over the Internet, on a subscription or purchase basis. More details about SaaS or Software as a Service.
A server is a computer, device or computing program that manages networking and computing resources, and provides services and functionalities to other computers, programs and devices known as “clients”.
The shared-responsibility model defines that the responsibilities related to the cloud security and data protection are shared between the cloud service provider and the customer. In this model, the Internet Service Provider is responsible for the security of the cloud and the customer is responsible for the security in the cloud.
An SLA or Service-level agreement is an agreement between the service provider (ISP) and the customer which collects the specific aspects of the service in terms of quality, availability and responsibility. Inside the SLA, ISPs define the level of service of the services contracted by the customer.
The concept “vendor lock-in” refers to the situation of dependency on a product or service where a customer can be “stuck” when wanting to change providers, since the change entails very high costs and application compatibility issues.
Virtualization is the process of creating a virtual technological resource with a layer of software that separates it from the hardware or physical resource (servers, applications, networks…).
A virtual machine or VM is a virtual environment created within a physical hardware system with an hypervisor. It has its own operating system, CPU, memory, network interface and storage.
A VPN or Virtual Private Network is a network that allows to create a private, encrypted and secure connection between two points over the Internet. VPN tunnels enables to send encrypted and secure traffic. More details about what’s a VPN.