Cloud computing & hosting definitions

IT & technology glossary

Cloud computing is flooded with technical jargon and industry buzzwords. The OVHcloud glossary is your guide through this confusing technical terminology. This glossary provides terms and definitions for Cloud computing and OVHcloud. Easily browse our list of IT terms and definitions using the letters below

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Anonymous FTP:

Anonymous FTP is a sub-category of FTP (File Transfer Protocol) that provides access to data without requiring a user ID or password (unprotected access). This protocol carries security concerns, and the system admin is responsible for ensuring that only appropriate data can be accessed.


Anti-DDoS protection is a type of solution designed to counter DDoS attacks. At OVHcloud, a VAC system detects and 'vacuums' illegitimate traffic that would otherwise cause your services to become unavailable. Anti-DDoS protection is applied by default to all OVHcloud services. See also: DDoS attack.

Application programming interface:

An Application Programming Interface (API) is a set of definitions and protocols. It liaises between two or more applications, enabling them to 'talk' to one another. App 1 sends a request to the API, API calls the server for app 2, retrieves the requested data, and returns it from app 2's server to app 1x

Artificial Intelligence:

Artificial intelligence refers to technology capable of performing tasks that would usually require human intelligence (e.g., decision-making, problem-solving). Real-world applications of AI include voice recognition, image recognition and customer support chatbots.

Availability rate:

Availability rate is a metric to measure the percentage of time for which a cloud service is available. The formula for this is: (Guaranteed time - Downtime) ÷ Guaranteed time. Commonly measured in 'nines', e.g., 'two nines' = 99.00%, 'four nines' = 99.99%. For critical services, a high availability rate is vital.


A backup is the process of creating copies of an entire IT system, or individual files. These copies are stored separately, so they can be restored if the original is lost or destroyed. There are different types of backup method (e.g. incremental backups, snapshot backups) to meet every budget and use case.


Bit rate is a measurement of the volume of data (in bits) that a system transfers from one location to another. Units include Bps (bit/s), Mbps (Mbit/s) and Gbps (Gbit/s) — 'bits per second', 'megabits per second', 'gigabits per second'. Bandwidth refers to the maximum bit rate a system is capable of delivering.

Bare metal:

Bare metal is technology that contains pure hardware, and nothing else. Bare-metal servers have no operating system installed, no virtualization layer, and no pre-installed applications. Users get full access to the hardware resources, and can install whatever operating system and programs they want.

Big data:

Big data refers to data sets that are too high in volume to process on a single high-end machine with a high level of attached storage. There are 3 Vs to big data: volume (the amount of data handled), velocity (the speed at which it is generated, received and processed), and variety (types of data received).

CDN Server:

The cloud refers to computing resources delivered over the internet, rather than running locally on a user's personal computer. These resources are sold on-demand by a cloud company, who maintains the hardware, power supply and cooling. Dedicated servers and public cloud instances are examples of cloud products.

Cloud Application:

A cloud application, or cloud app, is an application that is based on cloud computing resources and services. Cloud apps do not require a constant internet connection, but while offline, they cannot transfer data to or from remote components.

Cloud Architect:

A Cloud Architect is an IT expert who manages a company's cloud computing strategy. They design the cloud infrastructure to fit a project's technical requirements, and find ways to overcome the business challenges presented by cloud technology. They may also intervene in legal areas, e.g., contract negotiation.

Cloud Automation:

Cloud automation is the use of automation technology to perform tasks like resource provision, management and backup creation. Less human intervention is required, and IT teams can focus on value-added tasks rather than repetitive, time-consuming admin tasks.

Cloud Backup:

A cloud backup, or remote backup, is the strategy of storing copies of data in a secondary, off-site location — usually a datacentre managed by a cloud provider, who bills the customer for the amount of storage used. If the primary server goes down, the customer can then retrieve a backup stored safely elsewhere.

Cloud Bridge:

A Cloud bridge is a hardware device or software application that connects an on-premises system to a cloud network. Businesses can then adopt a hybrid strategy by extending their infrastructure into the cloud.

Cloud bursting:

Cloud bursting is a hybrid cloud deployment technique that uses cloud solutions (usually public cloud resources) to manage excess traffic or resource usage that would overwhelm the on-premises infrastructure. Cloud bursting can be triggered automatically or manually by adding a capacity threshold.

Cloud computing:

Cloud computing is the delivery of IT services over the internet on demand. These services are provided and maintained by a cloud provider. The alternative is on-premises computing, where IT equipment is hosted locally by the user. Cloud technology offers many benefits, e.g., more flexibility and cost control.

Cloud computing types:

There are 3 cloud computing types: public cloud, private cloud, and hybrid cloud. Public cloud resources are shared across multiple users. Private cloud resources are dedicated to a single user. Hybrid clouds combine on-premises resources with cloud services from a hosting company.

Cloud Desktop Infrastructure:

Virtual Desktop Infrastructure (VDI) is a virtualization solution that deploys and manages virtual desktop fleets. These desktops are hosted by a cloud provider, and accessed remotely from local devices by end-users.

Cloud Economics:

Cloud economics is the study of the financial costs, benefits and principles of cloud computing. Cloud economists analyse the market landscape, compare the return on investment (ROI) of a cloud strategy to that of on-premises hosting, and measure the total cost of ownership (TCO) of cloud technology.

Cloud Engineer:

A cloud engineer is an umbrella term for any IT expert whose responsibility involves cloud infrastructure design, maintenance, administration, planning and support. They usually have a specialism, which is designated in their job title: e.g., cloud software engineer, cloud security engineer, or cloud network engineer.

Cloud governance:

Cloud governance is a set of rules, policies and practices enforced to determine how a business runs services in the cloud. The purpose of a cloud governance framework is to provide enhanced IT security, manage risk, and avoid common pitfalls.

Cloud IDE:

A cloud integrated development environment (IDE) is a web-based, cross-platform programming solution. Since IDEs are used via web browsers, developers can manage code from anywhere and any device, with no downloads or installations required.

Cloud Management Platform:

Cloud management platforms (CMPs) are integrated software products that monitor and manage public, private and hybrid cloud infrastructures. They act as a centralized space for admins to check overall resource usage, billing, and monitoring, for example — and this data can then be used to optimize the IT system.

Cloud migration:

Cloud migration is the process of moving either part or all of an organisation's IT infrastructure (digital assets, data, databases, applications, etc.) to the cloud. This term is also used to describe the process of moving IT infrastructure from one cloud to another.

Cloud Native:

Cloud native is the concept of building applications specially designed to run in cloud environments. Cloud native programs are typically built using microservices — small, self-contained units of code that can be easily deployed and scaled using container orchestrators, for example.

Cloud operating system:

Cloud operating system describes 2 different OS types:
1) A client-side OS designed to load all applications from the cloud (the internet or a local network).
2) A server-side OS designed to manage cloud environments, and perform admin tasks (e.g. VM deployment, resource allocation).

Cloud Platform:

A cloud platform is an environment for designing, developing and managing applications in the cloud. The environment is delivered in the form of a service, and includes a set of tools that enables users to perform their day-to-day tasks.

Cloud Portability:

Cloud portability is the ability to move an IT system, applications and data between cloud providers. If a system has a high level of portability, it can be migrated seamlessly between providers, with no integration issues. Low portability leads to integration issues, incompatibilities and porting issues.

Cloud Provider:

A cloud provider is a company that delivers cloud-based products to its customers, on a pay-per-use or subscription basis. These products are referred to under the umbrella terms of IaaS, PaaS and SaaS. The cloud provider maintains the hardware aspect of its products so customers can focus on their core business.

Cloud Pyramid:

A 3-level pyramid diagram for the structure of cloud services. The lowest level is IaaS (the underlying infrastructure). The middle level is PaaS (where software developers build and run their applications). The top level is SaaS (the final product for end-users).

Cloud Security:

Cloud security is a broad term for the set of procedures, best practices and technologies put in place to protect against both internal and external threats to a cloud infrastructure. Both cloud hosting providers and customers are responsible for ensuring optimal security. Learn more about cloud security here.

Cloud service provider:

See: Cloud provider.

Cloud storage:

Cloud storage is when data is stored remotely by a cloud hosting provider. The data is then made available to users over the internet, or via a private network connection. Since the cloud provider manages the hardware, security, power and network, this is a cost-effective and flexible solution.

Cloud testing:

Cloud testing is an umbrella term for the range of tests carried out on cloud-based products. For example, they can be tested for availability (avoidance of downtime), latency (loading times worldwide), security (penetration testing), disaster recovery (to avoid data loss/destruction), and browser compatibility.

Cloud-Oriented Architecture:

A cloud-oriented architecture (COA) is a conceptual, abstract cloud model that encompasses all aspects of the cloud — i.e., the general structure of a cloud-based IT system, and the ways in which all its underlying components are connected to one another.


Containers are standard units of software containing all the code and dependencies needed for an app to run. This means they work seamlessly on any computing environment, and devs don't have to worry about compatibility issues. Containers are executed by runtimes such as Docker, within an orchestrator like Kubernetes.

Containers as a Service:

Containers as-a-Service (CaaS) is a cloud service that enables software developers and IT teams to upload, manage, deploy, organize and scale containers using container-based virtualization technology.

Content delivery network:

A Content Delivery Network (CDN) is a group of servers spread across the globe. It caches content from a primary server and delivers it as quickly as possible to web users worldwide. If a US-based user requests data from a primary server hosted in Sweden, the request can be redirected to a CDN server in North America.

Customer Relationship Management:

CRM (Customer Relationship Management) is an umbrella term for a company's approach to managing interactions with customers, and optimising customer experience. CRM tools are software programs used by companies as part of this strategy.

Data centre:

A datacentre is a building (or space within a building) designed to house all the components required to run a computing infrastructure. This includes the hardware itself (i.e., physical servers assembled by technicians and stored in racks), the power supply for the servers, and the network connection.

Dedicated server:

A dedicated server is a physical server allocated to a single user. The customer is responsible for server administration, and gets root access to their machine. The web hosting provider only intervenes to perform hardware maintenance, and act on user requests to change hardware (e.g. adding resources).

Deep learning:

Deep learning is a sub-category of machine learning. It is powered by neural networks with at least 3 layers, and is designed to mimic the learning patterns of the human brain. A deep learning algorithm is trained using big data, and differs from standard machine learning in that it processes unstructured data.

Disaster recovery plan:

A Disaster Recover Plan (DRP) is the process pre-emptively set up by an organisation to respond to both natural and man-made disasters that impact its IT system. It is designed to get the computing infrastructure back up-and-running as soon as possible, regain access to critical systems, and avoid data loss.

Distributed Denial of Service Attack:

A Distributed Denial-of-Service attack (DDoS attack) is a type of cyberattack where the perpetrator floods their target's server or IT infrastructure with requests from multiple remote locations. Unable to distinguish legitimate requests from those sent by the attacker, the service beomes unavailable as a result.


The Domain Name System (DNS) is a protocol that translates domain names (e.g., into IP addresses ( When a web user searches for a page online, they make a query. This triggers DNS resolution. The data or resource linked to the IP is then retrieved, and loads on the web user's device.

File Transfer Protocol:

File Transfer Protocol (FTP) is a standard process for transferring files between devices over the internet, and is now a popular way of storing files in the cloud. Webmasters can move files from one location to another using FTP client software programs such as FileZilla and Cyberduck.


A firewall is a network security device that monitors ingress and egress network traffic, and blocks unathorized traffic based on pre-set security rules. The most common firewall type is packet-filtering, which analyses whether the source and destination IPs of data packets match the rules.

Green cloud:

Green cloud is the adoption of an eco-friendly approach to developing and operating cloud services. A cloud provider may adopt a green cloud strategy by minimizing their power usage, reducing their carbon footprint, and re-using hardware components — lowering their environmental impact as a result.


Hacking is an umbrella term for any activity that compromises an IT network or infrastructure's security — e.g., gaining unauthorized access to a system, unauthorized control over a device, or data theft. Major companies employ ethical hackers to identify and report vulnerabilities in their IT systems.


A host is any kind of hardware device (usually a computer or server) that is connected to other devices via a network, has an IP address, and is capable of sending, receiving and storing data. Not all network devices are hosts. For example, intermediary devices like routers and switches are classed as nodes.

Host server:

A host server is a physical server that stores data, applications or virtual machines, and serves these resources to users. In the context of cloud technology, the server's hardware is managed and maintained by the hosting provider, and the customer is responsible for configuring it.

Hybrid cloud:

A hybrid cloud is an IT infrastructure that combines both on-premises and cloud-based environments. A hybrid cloud may include an on-premises server cluster and a group of Public Cloud instances, for example. Hybrid clouds are great for cost control, increased redundancy, and optimal efficiency.


A hypervisor, also known as a VMM (Virtual Machine Monitor), is a type of software or hardware installed on a physical server. Its purpose is to create, run, monitor and manage virtual machines (VMs) by allocating a portion of the host server's hardware resources to each machine.

Infrastructure as a Service:

Infrastructure as-a-Service (IaaS) is a type of cloud computing service that delivers virtualized resources (e.g. compute, storage space, CPU power, network resources) over the internet. It is billed on a subscription, pay-as-you-go or on-demand basis — so customers only pay for what they use, when they need it.

Internet of things:

The Internet of Things (IoT) is a network of devices that can interact and share data with one another online. Smart-home technology (e.g., smart heating systems with sensors, virtual assistants, and speaker systems) is an example of an IoT network.

IP Address:

An IP address (Internet Protocol address) is a unique string of numbers attached to a device, which makes it identifiable on the internet. Each address contains a series of 4 numbers, separated by full stops. The first 3 numbers in the series are referred to as the 'network ID', and the last number is the 'host ID'.

Load Balancer:

Load balancing is the process of distributing traffic evenly across a group of servers. It optimizes efficiency, and stops a single server from bearing too much demand. When a web user sends a query, the Load Balancer automatically detects which server can handle the traffic.


A log is a computer-generated file containing a detailed, time-stamped list of events that occur on an IT system (e.g., processes, user activity, errors, unusual behaviour). This is vital for monitoring web services, and detecting the root causes of issues or anomalous patterns that might occur on them.

Machine learning:

Machine learning is a sub-category of artificial intelligence that involves training a machine to imitate human behaviour. The machine 'learns' from high volumes of existing, usually structured data — and its end goal is to accurately predict outcomes without being explicitly programmed to do so.


Mitigation is the process of limiting, isolating, and minimizing the impact of a cyberattack on an IT infrastructure. OVHcloud's built-in Anti-DDoS protection is an example of mitigation technology that protects IT systems against DDoS attacks.

Network Attached Storage:

Network Attached Storage (NAS) is a device that consolidates data in a central location. Since it is attached to a network, multiple users and devices can access the data simultaneously — so it is perfect for collaborative working. A NAS device may contain a single hard drive or an entire RAID array.

Network file system:

A Network File System (NFS) is a mechanism for storing and distributing files and directories across a network. Since it is a distributed file system, users connected to the network can then access the files and directories as if they were stored locally — making it a user-friendly, cost-effective storage system.


NSX is a network virtualization and security platform released by VMware. Fundamentally, it is designed for users to manage virtual network deployments — but users can also access a wide range of services that optimize security and resource usage (e.g., load balancing, distributed firewall, security recommendations).

NVMe hard drive:

An NVMe (Non-Volatile Memory Express) hard drive is any solid-state drive (SSD) that uses NVMe as its storage access and transfer protocol. NMVe accesses flash storage via a PCI Express (PCIe) bus, which can support tens of thousands of queues simultaneously. This makes NVMe drives much quicker as a result.

Operating system:

An operating system (OS) is low-level system software that sits above a server's hardware. It manages hardware resources, as well as the software applications on it — coordinating the allocation of power for each program and task. The most commonly used OSs are Windows, MacOS, and Linux.

Platform as a Service:

Platform as-a-Service (PaaS) is a cloud computing model where the provider delivers everything required for users to build apps. On top of receiving the base hardware resources, users of PaaS services generally do not need to worry about operating system and database software management, for example.

Private Cloud:

A private cloud is a computing service that provides software and hardware resources dedicated exclusively to a single customer. This isolated, single-tenant environment combines the scalability of the cloud with the security of an on-premises infrastructure.

Public Cloud:

A public cloud is a computing model where a third-party provider delivers a platform shared between multiple users via the internet. Resources are delivered on either a pay-per-use basis, or via commitment-based plans. This is very useful for organizations that experience short-term, unpredictable spikes in traffic.


In computing, a rack is a type of frame that is used to store physical servers in datacentres, and connect them to a network. OVHcloud also offers the vRack (virtual rack) as an option for creating private connections between dedicated servers.


In computing, a redirection is a way to send web users to a webpage different from the one they initially request. This action is generally used when a webpage is no longer available, or when a company's brand name has changed, with its domain name changing as a result.


A snapshot is a backup technique that involves creating a copy of an IT system's current state at a specific point in time. These are particularly useful if the system fails, and needs to be restored to an earlier state.

Software as a Service:

Software as-a-Service (SaaS) is a computing delivery model where a third-party provider hosts software applications, and delivers them to end-users on a subscription basis. SaaS solutions are typically accessed via the end-user's web browser, so users don't have to install or maintain software on their own PC.

SQL Injection:

An SQL injection is a type of cyberattack where the hacker injects their own code into queries sent from an application to a database. For example, if a database stores sensitive data that requires a username/password, the hacker would instead input an SQL statement that fetches the sensitive data they are targetting.


Secure Socket Shell (SSH) is a network protocol that encrypts the data shared between two computers. It is vital for ensuring that file transfers and user access to IT systems remain secure.

Storage space:

In computing terms, a storage space is the available space on a server for storing all types of data. The methods for accessing a storage space may vary depending on the technology used.


In OVHcloud, the VAC is a vital part of the anti-DDoS technology built into all of our solutions. Short for 'vacuum', the VAC component filters out illegitimate traffic during a DDoS attack, so only legitimate traffic reaches the user's server.

Vertical Cloud:

A vertical cloud is a set of cloud computing services designed to suit a specific type of industry or business model. IT infrastructure and security requirements will vary significantly between healthcare organizations, government divisions, and educational establishments, for example.

Virtual machine:

A virtual machine (VM) is a 'guest' server created on the basis of a physical server (its host). A hypervisor allocates a portion of the host's hardware resources (CPU, RAM, storage) to each VM, and VMs can also run on different operating systems.

Virtual Private Cloud:

A virtual private cloud (VPC) is a private cloud environment delivered within a public cloud. Unlike VMs and VPSs, which are limited to a single host (physical server), a VPC is deployed across multiple servers within a datacentre. This makes it perfect for users with more fluctuating needs.

Virtual Private Server:

A virtual private server (VPS) is a type of web hosting platform that runs on the basis of virtualization technology. Users get guaranteed resources allocated from a physical server, and they are the VPS's root user — so they get a similar degree of flexibility and control as a dedicated server, but for a lower price.

Virtual rack:

The vRack (virtual rack) is a private network solution that links a user's dedicated servers to one another across the globe via a virtual switch. In short, it works like a VLAN. It is either included or available as an option, depending on the Bare Metal server you choose.


Virtualization is a type of technology that partitions a physical server's hardware resources into multiple, separate portions. These portions can then be used for various purposes — e.g., delivering virtual private servers to different users. Usually, a hypervisor is used to virtualize hardware resources.


vSphere is the virtualization platform released by VMware, which includes a suite of products to optimize and simplify cloud infrastructure deployments. OVHcloud includes a managed version of this platform and licence in all of its Hosted Private Cloud packs.