IT glossary

IT terms, in plain English.

58 terms you will meet in quotes, security questionnaires and Microsoft 365, each explained in a sentence or two, with a link to where we go into more detail.

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3-2-1 backup rule

Keep three copies of your data, on two different types of storage, with one copy off-site. A modern version adds one copy that is offline or immutable, and zero errors when restores are tested.

A

Acceptable use policy(AUP)

A short document that sets the rules for how staff may use company technology, such as AI tools, email or devices, including what information may be shared and with which services.

Auto-attendant

The recorded menu that answers a business phone number ("press 1 for sales") and routes callers to the right person or team, with different routing for business hours, evenings and holidays.

Azure

Microsoft's cloud computing platform. Businesses use it to run servers, applications, databases, backups and virtual desktops in Microsoft data centres instead of on hardware in their own office.

Azure Virtual Desktop(AVD)

A Microsoft service that runs Windows desktops and applications in Azure and streams them to any device, so staff get the same managed desktop from the office, home or on the road.

B

Backup

A separate copy of data kept so it can be restored after deletion, corruption, hardware failure or ransomware. A good backup is separate from the original, versioned, protected from deletion and regularly tested.

Business continuity and disaster recovery(BCDR)

The combination of backups, recovery procedures and planning that keeps a business running through an outage or data loss: restoring systems within an agreed time, and keeping people working meanwhile.

Business email compromise(BEC)

A scam in which criminals impersonate or take over a business email account, typically to redirect payments or request sensitive information from staff, clients or suppliers.

C

Conditional Access

A Microsoft Entra ID feature that decides whether to allow a sign-in based on conditions such as location, device health and risk, for example requiring MFA or blocking unmanaged devices. It is included in Microsoft 365 Business Premium.

Copilot(Microsoft 365 Copilot)

Microsoft's AI assistant built into Word, Excel, PowerPoint, Outlook and Teams. The paid Microsoft 365 Copilot licence works with the emails, files and meetings the user can already access.

D

Data loss prevention(DLP)

Policies that detect sensitive information, such as credit card or health numbers, and stop it being shared where it should not go, for example in an email to an outside address.

DKIM(DomainKeys Identified Mail)

An email authentication method that adds a cryptographic signature to outgoing messages, so receiving servers can confirm the message really came from your domain and was not altered.

DMARC

A DNS record that tells receiving mail servers what to do with messages that fail SPF and DKIM checks for your domain (monitor, send to spam or reject) and sends you reports about who is sending as you.

DNS(Domain Name System)

The internet's address book. DNS records for your domain say where your website lives, which servers receive your email, and which services may send email on your behalf.

DNS filtering

A security control that blocks connections to known malicious or unwanted websites at the point a device looks up the address, before the page ever loads.

E

Endpoint

Any device that connects to your systems: laptops, desktops, servers, phones and tablets.

Endpoint detection and response(EDR)

Security software that watches how devices behave, rather than only matching known viruses, and can detect and contain an attack, for example by isolating a compromised laptop from the network.

Entra ID(formerly Azure Active Directory)

Microsoft's identity service behind every Microsoft 365 sign-in. It holds user accounts, groups, passwords, multi-factor authentication and the policies that control access.

Exchange Online

The email, calendar and contacts service inside Microsoft 365. It is what Outlook connects to.

F

Firewall

The device or service at the edge of your network that controls which traffic may come in and go out. Next-generation firewalls add intrusion prevention, web filtering and application control.

FSLogix

Microsoft technology that stores each user's profile separately from a virtual desktop, so their settings and files follow them whichever session host they sign in to.

H

Hallucination

When an AI tool produces information that sounds convincing but is wrong or invented, such as a fake statistic, quote or source. It is why AI output needs checking.

I

Immutable backup

A backup that cannot be changed or deleted for a set period, even by an administrator, so ransomware or an attacker with admin access cannot destroy it.

Intune(Microsoft Intune)

Microsoft's device management service. It enrols laptops and phones, applies security settings and updates, deploys apps, and can remove company data from a lost or departing device.

J

Joiner, mover and leaver process

A documented routine for giving new staff the right access on day one, adjusting it when roles change, and removing it the moment someone leaves.

L

Least privilege

The principle that each person and system gets only the access it needs to do its job, and no more, so a compromised account can do less damage.

M

Managed service provider(MSP)

A company that takes ongoing responsibility for a business's IT for a regular fee, typically covering support, monitoring, security, maintenance and planning.

Microsoft 365 tenant

Your organisation's own instance of Microsoft 365: its users, domains, mailboxes, files, licences and settings. It should always be registered in the business's name.

Mobile application management(MAM)

Protecting company data inside specific apps, such as Outlook and Teams, on personal phones, without managing or seeing anything else on the device.

Mobile device management(MDM)

Full management of company-owned phones, tablets and laptops: enrolment, security settings, updates, apps and the ability to wipe the device.

Multi-factor authentication(MFA)

Requiring a second proof of identity at sign-in, such as an authenticator app, a security key or a fingerprint, in addition to a password, so a stolen password alone is not enough.

N

Network segmentation(VLANs)

Dividing one network into separate zones, such as staff, guests, phones and cameras, with rules between them, so one compromised device cannot reach everything.

Number porting

Moving an existing phone number from one provider to another so the business keeps it. In Canada, business numbers, including toll-free numbers, can be ported.

O

OneDrive

Personal cloud storage for each Microsoft 365 user, meant for their own work files. It syncs to their computer and is removed after a retention period when the account is deleted.

Oversharing

Files and sites that are shared more widely than they should be, for example with everyone in the company or anyone with a link. AI assistants can surface overshared content to the wrong people.

P

Passkey

A phishing-resistant way to sign in using a device's fingerprint, face recognition or PIN instead of a password. It only works on the genuine website, so it cannot be captured by a fake sign-in page.

Patch management

Applying security and software updates to operating systems and applications on a schedule, and tracking what is still missing.

Phishing

Fraudulent messages designed to trick people into revealing passwords, opening malware or sending money, usually by impersonating a trusted company or colleague.

Power Automate

Microsoft's workflow automation tool. It carries out rule-based tasks across Microsoft 365 and other apps, such as filing email attachments, routing approvals and sending notifications.

Prompt

The instruction or question you give an AI tool. Clear prompts with context and a stated goal produce far better results than vague ones.

R

Ransomware

Malware that encrypts a business's files and systems and demands payment to unlock them, often after first stealing data. Offline or immutable backups are the main defence against losing everything.

Recovery point objective(RPO)

The maximum amount of data, measured in time, that a business can afford to lose. Backing up nightly means up to a day of work could be lost.

Recovery time objective(RTO)

How long a system can be unavailable before the outage seriously harms the business.

Remote monitoring and management(RMM)

Software a managed provider uses to watch devices and servers for problems, apply updates and fix issues remotely, often before the user notices.

S

Security defaults

A free baseline in Microsoft Entra ID that turns on MFA for all users and blocks older, insecure sign-in methods. Conditional Access replaces it when more control is needed.

Sensitivity labels

Tags in Microsoft 365, such as Confidential, applied to documents and email that can restrict who may open them and how they may be shared, wherever the file goes.

Service level agreement(SLA)

The written commitment in a support agreement that defines response and resolution targets, hours of cover and how problems are prioritised.

Shadow AI

Staff using AI tools the business has not approved, usually on personal accounts, which means company data can end up in services with no agreement, control or record.

SharePoint

The document management platform in Microsoft 365. It stores team and company files in sites and libraries, with permissions, version history and search, and sits behind the files in Microsoft Teams.

Single sign-on(SSO)

Signing in to many applications with one company account, such as a Microsoft 365 login, so access can be controlled and removed in one place.

SIP trunk

A connection that carries phone calls over the internet between a phone system and the public phone network, replacing traditional phone lines.

SPF(Sender Policy Framework)

A DNS record that lists the services allowed to send email for your domain, so receiving servers can spot messages sent by anyone else.

SSL/TLS certificate

The certificate that lets a website load over HTTPS, encrypting traffic and showing the padlock. Certificates expire and must be renewed, ideally automatically.

T

Ticket

A logged support request with a reference number, priority and history, so every issue is tracked from report to resolution.

V

VoIP(voice over internet protocol)

Phone calls carried over the internet rather than traditional phone lines. Business VoIP systems run in the cloud, so the same number rings on desk phones, mobile apps and Teams.

VPN(virtual private network)

An encrypted connection that lets staff reach the office network or company systems securely from elsewhere.

W

Windows Autopilot

A Microsoft service that lets a new Windows laptop set itself up with company settings, apps and security when the employee first signs in, with no manual imaging.

Z

Zero trust

A security approach that verifies every user, device and request before granting access, rather than trusting anything simply because it is inside the office network.

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