IT Infrastructure glossary

This IT infrastructure glossary defines, in a single sentence, the key terms you will come across in our courses: virtualisation, monitoring, cloud, networks, backup… Each definition stands on its own and, where relevant, points to the related course or catalogue.

IT infrastructure

IT infrastructure is the whole set of servers, networks, systems and services that keep an organisation’s information system running.

Operating system (OS)

An operating system (Windows, Linux…) manages the hardware and runs the applications; it is the base layer of a server or a workstation.

Linux

Linux is a widely used open-source operating system on servers; Red Hat is a professional distribution of it. See the Open Source catalogue.

Server

A server is a machine, physical or virtual, that provides services (files, web, database…) to other machines on the network.

Virtualisation

Virtualisation lets several virtual machines run on a single physical server, making better use of resources. See Hyper-V.

Hypervisor

A hypervisor (VMware ESXi, Hyper-V…) is the software that creates and manages virtual machines on a host server.

Virtual machine (VM)

A virtual machine is a software-emulated computer with its own operating system, isolated from the other VMs on the same host.

vSphere / ESXi

vSphere is VMware’s virtualisation platform, built on the ESXi hypervisor. See the vSphere 8 course.

Backup

Backup copies data and VMs so they can be restored after an incident; Veeam is a leading solution. See the Veeam v13 course.

Monitoring

Monitoring continuously watches the health of servers, networks and services and raises alerts on anomalies. See Centreon and the Monitoring & Virtualisation catalogue.

Cloud computing

Cloud computing delivers computing resources on demand over the internet, in IaaS, PaaS or SaaS models. See the Cloud catalogue.

IaaS / PaaS / SaaS

Three cloud models: IaaS (infrastructure), PaaS (development platform) and SaaS (ready-to-use software).

Network (LAN / WAN)

A network links machines: a LAN is local (an office), a WAN spans long distances (sites, the internet). See the Networks catalogue.

Routing & switching

Switching directs traffic within a local network; routing moves it between networks. These are the core functions of switches and routers.

Firewall

A firewall filters network traffic according to security rules to protect systems from unauthorised access.

Active Directory

Active Directory is Microsoft’s directory service that centralises authentication and the management of accounts and workstations within a domain.

Microsoft 365

Microsoft 365 brings together email (Exchange), collaboration (SharePoint, Teams) and device management (Intune) in the cloud. See the Microsoft 365 catalogue.

High availability (HA)

High availability aims to keep a service reachable despite failures, through redundancy and automatic failover.