Jargon Busting for all

Confused by the many acronyms and terms used in the technology industry?
Use our Jargon Buster to discover the A-Z behind technology terminology.


In generic terms, any piece of software – business or consumer – such as email, CRM, etc.  The application server could reside on-premise (e.g. in a server room) or off-premise (e.g. in a managed cloud hosting environment).  The application itself will be either simple or complex in nature.

Application Hosting

One of the two “classic” hosting requirements (along with web hosting) whereby a company moves some or all of their business software from an on-premise deployment to an off-premise hosting environment.  This environment could be cloud, dedicated server or colocation based.


A type of long-term storage – typically years not months – whereby a customer moves their data from a “live storage” or backup environment.


A process whereby a business regularly (usually daily or twice daily) backs up their entire data estate to an alternative location. Historically, this backup was done to tape, but is now often done online using a cloud-based service.  Backups can be “managed”, e.g. performed by a provider as a managed service or “unmanaged”, e.g. the customer does it themselves or uses a self-service approach.

Business Continuity

From a technology perspective, a business continuity solution allows a company and its users to keep working in the event an incident prevents them from accessing their office (e.g. weather, criminal activity, health pandemic, etc). Not to be confused with disaster recovery which is similar, but not the same.


Storing data (a cache) in a local environment to improve the speed of accessing this data. On a small scale, it could be web browser cache. On a large scale, it would involve storing large files (like video) in multiple places to save distributing it all from one central location – using a content delivery network to facilitate.

Centralised IT

The concept whereby rather than each office or location having its own separate (distributed) IT resources, they are centralised in one location: all accessed over either a private network or the Internet.  So a company with six offices wouldn’t need six email servers, only one. The centralised location could be on-premise or off-premise.

Cloud Computing

A means of delivering computing using shared or dedicated resources that are housed on a secure centralised platform, rather than using the customers’ own servers.  See our Cloud Hosting Information for more details.


See colocation.


A hosting service whereby computing resources are stored in a third party data centre in colocation racks.  The colo racks can be shared, quarter racks, half racks, full racks or large pods/suites of many racks. The colo hosting provider (data centre operator) provides space, power, cooling and many different levels of resilience and redundancy in the technical provisioning.  Some data centres also provide managed services to support higher levels of The Hosting Stack than just raw facilities.

Complex Application

An item of software like Customer Relationship Management (CRM), Enterprise Resource Planning (ERP) or a line of business application like finance or billing.  It is complex in nature as it is usually highly customised to each customer’s unique business, making them generally single-instance­ as opposed to multi-tenant set-ups.  They are distinct from simple applications.

Content Delivery Network

Also known as Content Distribution Network.  A CDN is a set-up of servers (invariably large scale) distributed around a geographical area (usually international) whereby the same content is cached locally so that users can access the content more reliably and more quickly.   Typically, this set-up would be used for very complex web hosting projects for sites involving huge files (streaming videos, for instance) intended for consumption by a global audience.

Data Centre

A purpose-built facility for housing ICT resources, e.g. computing servers and telecommunications equipment.  Very large enterprises (e.g. Facebook, Google) operate their own facilities.  Others are “carrier neutral” and make up the points of presence for telecoms firms to build their networks and that make up the Internet’s backbone.  Some are expressly used to provide colocation services to business customers.  Data centres are also the “homes” of cloud services.

Dedicated Server Hosting

A form of hosting whereby dedicated server(s) are provided to the customer on a monthly rental basis with the server(s) being utilised only by one individual customer (as opposed to shared server hosting).  The term “dedicated server” is often used as a synonym for “managed hosting”.  Dedicated servers lack the virtualisation capabilities of cloud machines, but the use case and usage models are broadly similar.

Disaster Recovery

In technology terms, it is a service whereby, in the event of a catastrophic outage (complete loss of servers or complete loss of the site providing centralised IT) of an IT platform, one can recover the chosen data, systems, etc. as specified within a disaster recovery (DR) plan.  The DR plan could involve a whole dedicated facility, including desks and real estate, being available at a moment’s notice.  Today, DR is typically a hosted virtual service that builds upon backup services by making computing resources available, thus allowing full IT service to be restored.

Hybrid Cloud

A combination of two or more clouds, e.g. public cloud and private cloud, working together in parallel.


An intelligent piece of software that “manages” the virtual machines that reside on the physical servers in a cloud deployment.  The hypervisor will also manage value-added services like high availability mode and other virtualisation services.


See Infrastructure as a Service.

Infrastructure as a Service

The first few layers of the hosting value chain whereby cloud-based infrastructure (e.g. compute and storage) is provided as a Service for a time-based rental model (per minute, hour, day, week, month, etc.).

LAMP Stack

LAMP stands for Linux, Apache, MySQL and PHP.  These combine to form a software stack that can be used for building web servers (and/or application servers). The LAMP stack is an open source alternative to, for instance, Microsoft Windows, SQL Server and ASP.NET.

Live Storage

A live storage environment is where the data that is actively being used is stored, as opposed to a backup or archiving environment.  In a typical on-premise deployment, the pizza-box servers contain both compute and live storage resources in the same hardware.  In a cloud deployment, they are physically separate with virtual machines providing the compute resources and a large SAN.

Managed Backup

See Backup.

Managed Cloud Hosting

A form of managed hosting whereby the technology platform is based on cloud virtual machines as opposed to dedicated server hosting.

Managed Hosting

Managed hosting services originally began with dedicated servers whereby either application hosting or web hosting was delivered through a managed service.  Managed hosting is different to self-service hosting models because the hosting provider handles technical configuration, ongoing support and all elements that make up the hosting environment.  An SLA (Service Level Agreement) would govern how the service is delivered with roles and responsibilities defined in the managed hosting contract that exists between the provider and customer.

Managed Services

In a technology context, a managed service would involve a service provider working in conjunction with a business customer to deliver a defined suite of services designed to deliver certain business outcomes.  A Service Level Agreement (SLA), enshrined in contract, defines the responsibilities of the service provider.  In a hosting context, these responsibilities would be managed hosting services.  Managed services are often, wrongly, thought to be the same thing as outsourced services.

Monthly Recurring Revenue

MRR is a term used by service providers and industry analysts to describe a service that is delivered as part of an annual or multi-year contract, for a fixed monthly fee, as opposed to a pay-as-you-go approach to sourcing services.


See Monthly Recurring Revenue.


A form of Software as a Service platform whereby the customer can have their own customised instance of the application, as opposed to a classic multi-tenant approach.  Multi-instance makes it more suitable for the differing requirements of complex applications.



A form of Software as a Service platform whereby there is only a single-instance of the application that is deployed to all users.  The service provider controls all configuration and changes with little or no customisation available. Typically, this approach is one-size-fits-all that is more suited to simple applications.


A means of delivering centralised IT services from an off-premise hosting environment. The delivery of these services could be through colocation, dedicated servers or cloud hosting.


Also known as CPE (customer premises equipment), on-premise is the traditional way of delivering IT services. An on-site server room or data centre environment is used to host all of the IT and telecommunications equipment used by the company, managed by in-house IT staff or through an outsourced service.

Outsourced Services

An outsourcing contract would typically involve a company making the strategic decision to outsource some or all of their IT requirements to a third party service provider on a long-term contract basis.  Often wrongly confused with managed services.


See Platform as a Service.

Pay As You Go

In a technology environment, a way of sourcing services whereby the customer pays for them as they use them, after the fact, as opposed to an MRR approach.  This pricing model is analogous to mobile phone contracts, e.g. the user can opt for PAYG or a fixed monthly contract.


See Pay As You Go.

Platform as a Service

A PaaS offering provides a suite of tools designed to provide the necessary database, management, development and deployment tools for the creation and delivery of business applications, mobile apps, social apps, microsites, websites, and other software-driven solutions.

Private Cloud

A form of cloud whereby the hardware, virtual machines and storage is deployed on dedicated hardware for one company only.  This cloud is a single-tenant environment (as opposed to multi-tenant) and is distinctly different to public cloud, albeit with the same technologies used in the solution architecture.

Production Environment

In an application hosting or web hosting scenario, the production environment is the live, customer/company facing deployment of that which is being hosted.  Typically, the service would move into the production environment following a successful staging environment phase.

Public Cloud

A form of cloud deployed on multi-tenant platforms, invariably very large, often spanning multiple locations and countries.  These are called “public” clouds because they are accessed over the public Internet and are configured/managed through web portals.  Their size means they are highly elastic and scalable, far more so than private cloud deployments.  They are usually paid for in a PAYG model with highly granular usage-based tariffs across a variety of items.


The acronym stands for Redundant Array of Independent Disks.  In short, software-based intelligence provides “logical drives” that spread the data load across multiple disks for added resilience and redundancy.


In technology use, redundancy means that, for any piece of the technical jigsaw, there is a redundant component ready to be used in the event of failure.  Terms like “N+1” mean that there’s an extra unit available or “N+N/2N” would mean that there’s a like-for-like redundancy.  In an N+1 data centre, if 6 air conditioning units are needed, there would be a 7th as backup.  In an N+N data centre, there would be 6 backup units.


See Software as a Service.


See Storage Area Network.


In a cloud hosting scenario, self-service would typically mean that the user or business is responsible for configuring their own deployment. Self-service is in contrast to a managed hosting scenario.  Self-service models are typically seen in public cloud situations.

Service Level Agreement

An SLA, in a technology context, defines a number of service elements in the supplier’s contract.  These could include delivery time, uptime, performance levels, support levels and areas of responsibility for both supplier and customer.  Service credits are often in place to compensate the customer in the event of an SLA breach.  In a cloud environment, SLAs are associated with managed hosting services.  This is in contrast to public cloud or self-service models that typically either have no SLA at all or a rudimentary SLA that only governs the platform, not any specific customer requirements.

Simple Application

An item of software like email, instant messaging or collaboration that is “simpler” than a complex application (like CRM or ERP).  Customisation is typically limited at a company level with the configuration being at a user (or mailbox) level. Simple applications are regarded as being well-suited to multi-tenant or software as a service models.


In application software terms, a single-instance model is a situation whereby there is only one base configuration of the software.  Typically, this means it is dedicated to one company, usually bought and owned by them.  It could be considered the “traditional” means of supporting software.  Some multi-tenant or software as a service deployments are based on a single-instance model.


In hosting terms, a single-tenant environment is one that is dedicated to a single customer only, e.g. a private cloud.  The term is used in the industry to differentiate between shared or multi-tenant platforms.

Shared Server Hosting

A subset of dedicated server hosting whereby several customers share the same physical server.  Shared Server Hosting is normally only for individual consumers or very small businesses, e.g. for web hosting of simple sites.


See Service Level Agreement


Used in a backup scenario, snapshotting provides a “snapshot” at a specific point in time for data restore purposes.  For example, the company itself may wish to restore everything to the previous day’s snapshot (in the event of large scale data loss) or an individual has deleted a file and wishes to retrieve it from the backup drive.

Software as a Service

In a SaaS model, the cloud service provider is responsible for all technical elements from infrastructure, through to the platform and the application itself.  The customer will typically pay on a “per user, per month” model, e.g. if they wish to rent Microsoft Exchange mailboxes, this is delivered by the provider from their multi-tenant platform.

Staging Environment

In an application hosting or web hosting scenario, the staging environment follows successful exit from the testing environment and is the precursor to moving to the production environment.  Typically, staging would involve further User Acceptance Testing (UAT) work, service hardening and other technical work designed to prepare the service for full-scale production use.

Storage Area Network

A SAN “pools” a significant amount of disks into a logical network, separating the storage from the compute.  All cloud providers use some form of SAN for live storage and/or backup/archiving purposes.

Testing Environment

In an application hosting or web hosting scenario, the testing environment is used for development and initial UAT work as a precursor to the staging and production environment work. “Dev servers” are used for initial service trials, customisation, modification, bug fixing and the like.  Cloud virtual machines provide an ideal environment for so-called “test and dev” servers as they can be spun-up quickly and inexpensively and are only used for the time they are needed.

“Test and Dev”

Industry shorthand for the development servers used for initial application or web service building and testing.  See Testing Environment.


See User Acceptance Testing.

User Acceptance Testing

A process whereby the customer tests and confirms that the application or web service meets the requirements defined in the scope of work for the technical project.  UAT usually occurs at the staging environment phase of the project, prior to moving to a production environment.


See virtual desktop infrastructure.

Virtual Desktop Infrastructure

A set-up whereby user configurations and desktop software sit in a central environment and are delivered to the client PCs (and other devices like tablets) that the users log on to. Therefore, instead of upgrading each PC, the customer (or their service provider) upgrades only the core platform.


In a technology environment, a concept whereby the logical entity (like a network, server or desktop platform) is separated from the physical entity (the hardware itself).  In a cloud hosting situation, virtualisation would mean that virtual machines perform the functions historically provided by dedicated servers, offering significant performance and resilience advantages.

Virtual Machines

In a computing context, a virtual machine (made popular by VMware) replicates the tasks performed by a physical server.  Conceptually, several virtual machines can reside on a single physical server, thus saving significantly on hardware costs.  In a cloud environment, this is scaled up considerably to spread VMs over multiple server blades to deliver highly available, highly scalable computing resources.  Thanks to the scale of cloud platforms, especially public cloud, resources can now be rented for very short amounts of time, offering greater flexibility and cost savings compared to buying dedicated hardware.

Virtual Private Cloud

A form of cloud deployment that combines the traits of public cloud and private cloud. A VPC is delivered on a multi-tenant (shared) platform, but the VMs themselves are dedicated to the specific customer with firewalling, load balancing and private network connections typically included in the package.


See Virtual Private Cloud.

Web Hosting

One of the two “classic” hosting requirements (along with application hosting) whereby a company hosts their website in a third party provided hosting environment.  This hosting environment could be cloud, dedicated server or colocation based.  Typically, the web hosting provider will offer extremely high-speed Internet connectivity, with diversity and resilience across the network, to ensure that the company’s website is highly available.  The web hosting service will need to be configured – either through self-service or managed hosting – to be able to handle the day-to-day traffic requirements and any known (or unknown) traffic peaks.