- 3-2-1 rule
- Keep 3 copies, on 2 media types, with 1 off-site.
- Access point
- Adds Wi-Fi, letting wireless devices join the wired network.
- Account
- A user's identity on a system, carrying rights and permissions.
- Account takeover
- An attacker signing in as a user, usually via a stolen or guessed password — what MFA blocks.
- Active Directory (AD)
- Microsoft's directory service, organizing objects into a domain.
- Active listening
- Fully hearing the user out, asking clarifying questions, and confirming understanding before acting.
- Appetite / aptitude / market
- The three inputs to choosing a path: what you enjoy, what you're good at, what's in demand.
- Attack surface
- Everything an attacker could target; reducing it (hardening) means less to attack.
- Automation
- Encoding a task once so it runs reliably and identically, at scale.
- Backup
- A copy of data kept so it can be recovered after loss, corruption or attack.
- Backup frequency
- How often you back up, driven by how much recent data you can afford to lose.
- Bit
- The smallest unit of information: a single 1 or 0.
- Bootable media
- A USB drive prepared to start the computer and run the Windows installer.
- Box (all-in-one)
- A single unit that combines modem, router, switch and access point in small setups.
- Bus factor
- The risk that too much knowledge lives in one person; documentation reduces it.
- Business continuity
- Keeping essential activity running during an incident, not just recovering after it.
- Byte
- Eight bits; the basic unit for data size (KB, MB, GB, TB).
- Certification
- A credential that structures learning, validates knowledge and improves visibility.
- Change management
- A controlled way of making changes to reduce the risk of disruption.
- Clean install
- Installing Windows fresh on a wiped disk, as opposed to upgrading over an existing system.
- Client-server
- A model where a client requests a service and a server provides it.
- Cloud
- Consuming computing as a service over the internet, paying for what you use.
- Command line
- A text interface for instructing the computer, faster and more repeatable than clicking for many tasks.
- Consolidation
- Replacing many under-used physical servers with VMs on fewer hosts, using hardware efficiently.
- Continuous learning
- The durable habit of keeping up as technology evolves — the real career skill.
- CPU / RAM / storage
- Processor (does the work), memory (fast, temporary working space), storage (keeps data long-term: SSD or HDD).
- Criticality
- How essential an activity is, used to set its RPO/RTO targets.
- Default gateway
- The exit point of the local network (usually the router) used to reach machines outside it.
- Defense in depth
- Layering multiple protections so that if one fails, others still hold.
- DHCP
- The service that automatically assigns IP addresses and network settings to devices joining a network.
- Directory service
- A central store of accounts, computers, groups and rights for an organization.
- Disaster recovery (DR)
- The plan and means to restart IT services after a serious disruption.
- DNS
- The service that translates domain names (example.com) into IP addresses — the internet's phone book.
- DNS server
- A machine that answers name-to-address questions; devices are usually told which one to use by DHCP.
- Document while you do
- Writing the note as you make the change, rather than 'later'.
- Domain
- A managed group of accounts and computers under one central administration.
- Domain join
- Bringing a computer under the domain's central management.
- Driver
- Software that lets a specific piece of hardware work with the OS.
- Empathy
- Acknowledging the user's frustration and situation, which makes them easier to help.
- Escalation
- Passing an issue to a higher tier or specialist, with the context already gathered.
- External sharing
- Settings that control whether and how files can be shared with guests outside the organization.
- File format / extension
- The type of a file, hinted by its extension (.pdf, .jpg, .docx), which tells software how to open it.
- File system
- The way an OS organizes data into files and folders on a storage device.
- Firewall
- A control that decides which network traffic is allowed.
- Follow-up
- Checking back so users know their issue was not forgotten.
- Foundational path
- A common sequence such as CompTIA A+ → Network+ → Security+ before specializing.
- Gateway ping
- Pinging the default gateway to confirm the local network is reachable.
- Generalist foundation
- A broad base across hardware, OS, networking, accounts, cloud and security, built before specializing.
- GPO (Group Policy Object)
- A bundle of settings pushed automatically to targeted computers and users.
- Group
- A collection of users given permissions together, so access scales and stays maintainable.
- Group Policy
- The mechanism that applies settings and rules to domain computers and users centrally.
- Group-based access
- Assigning permissions to groups rather than individuals, so access stays maintainable.
- Hardening
- Disabling unnecessary features, services and accounts to shrink the attack surface.
- Hardening via GPO
- Using policy to enforce security settings consistently across the estate.
- Hypervisor
- The layer that lets multiple VMs share one host's hardware.
- IaaS
- Renting raw infrastructure (virtual servers, storage, network); you manage the OS and up.
- Identity as perimeter
- In the cloud, security centers on protecting sign-ins, since there is no physical network boundary.
- Incident vs problem
- An incident is a single disruption to fix fast; a problem is the underlying cause of repeated incidents.
- Information system
- The whole set of hardware, software, data, networks and people that lets an organization store, process and share information.
- Infrastructure docs
- How the network, servers and access are configured.
- Inheritance
- The way permissions set on a folder flow down to the items inside it.
- Inventory
- The maintained list of assets — the foundation for security, licensing, support and planning.
- IP address
- The identifier of a machine on the network (e.g. 192.168.1.10) used to send and receive data.
- ipconfig
- Command that shows the machine's own IP configuration (address, mask, gateway, DNS).
- Isolate
- Narrow the problem down: hardware or software, one machine or many, one user or all.
- IT (information technology)
- The function that runs, secures and evolves the information system the business depends on.
- IT asset management
- Keeping a current inventory of hardware, software and licences across the estate.
- ITIL
- A widely used framework of IT service best practices — to adapt, not apply to the letter.
- ITSM
- IT Service Management: running IT as structured services delivered to the organization.
- Jargon
- Technical vocabulary that is precise for you but confusing for the user; avoid it when explaining.
- Kernel
- The core of the OS that talks to the hardware and shares its resources among programs.
- Knowledge base
- A written record of problems and their solutions, so fixes are reusable.
- Least privilege
- Granting only the access each person genuinely needs, and no more.
- Licence
- An assignment that unlocks a set of Microsoft 365 services for a user; you pay per assigned licence.
- Link / scope
- Attaching a GPO to the domain or an OU so it targets specific machines or users.
- Linked site/group
- Creating a Team automatically creates a SharePoint site and a group behind it.
- Linux
- A free, open-source OS family that dominates servers and cloud infrastructure.
- macOS
- Apple's OS, common in creative fields, running only on Apple hardware.
- Managing expectations
- Being honest about what you can do and by when, including when you must escalate.
- MFA (multi-factor authentication)
- Requiring a second proof of identity beyond the password.
- Microsoft 365 admin center
- The cloud console for administering users, licences, groups and services.
- Microsoft Entra ID
- Microsoft's cloud identity service managing accounts, groups and access.
- Modem
- The device that terminates the provider's line and converts it into a usable network signal.
- Name resolution
- The act of turning a name into an address via DNS.
- Network profile (private/public)
- Windows setting that treats a network as trusted (private) or untrusted (public), affecting sharing.
- Offboarding
- Blocking or removing a departing user's account and reclaiming the licence.
- Offline / immutable copy
- A disconnected or unchangeable copy that ransomware cannot reach or alter.
- OneDrive
- Personal cloud storage for a user's own files, private until shared.
- Open-source licence
- A licence for freely available source code, still with terms you must respect.
- Operating system (OS)
- The software that sits between hardware and applications; it manages memory, files, processes and devices.
- Organizational unit (OU)
- A container that arranges directory objects to mirror the company's structure.
- Outward-in method
- Diagnosing from the local machine to the wider network, step by step.
- PaaS
- Renting a ready platform to run your applications; you manage the app, not the servers.
- Patching / updates
- Applying fixes that close known vulnerabilities — the most common entry point when neglected.
- Per-user / per-device
- Licensing counted by named users or by installed devices — a common source of compliance mistakes.
- Peripheral
- A device attached to a computer — input (keyboard), output (monitor, printer) or storage (external drive).
- Permissions
- The rules that decide who can access a share and at what level (read, or read/write).
- Perpetual vs subscription
- A perpetual licence is bought once; a subscription is paid periodically and stops when you stop paying.
- ping
- Command that tests whether a target responds on the network.
- PowerShell
- Windows' modern command shell and scripting language, working with structured objects.
- Precedence
- The rules that decide which setting wins when multiple GPOs apply.
- Private address / NAT
- Internal addresses not routable on the internet (192.168.x.x, 10.x.x.x); NAT translates them to the public address.
- Privileged account
- An administrator identity, protected most strongly because it can change everything.
- Procedures
- Step-by-step instructions for performing tasks reliably.
- Redundancy
- Duplicating critical parts (power, disks) so the service keeps running if one fails.
- Reproduce
- Make the problem happen on demand so you can observe it and test whether it is fixed.
- Request-response
- The pattern where a client asks and a server answers, underlying most web traffic.
- Restore test
- Actually recovering from a backup to prove it works — the step most often skipped.
- Rights vs permissions
- Rights are what an account may do on the system; permissions are what it may do to specific files and folders.
- Router
- Connects different networks (LAN and internet) and forwards traffic; usually the gateway, DHCP server and NAT.
- RPO (Recovery Point Objective)
- How much data you can afford to lose, in time — it drives backup frequency.
- RTO (Recovery Time Objective)
- How long you can afford to be down before restoring service — it drives recovery resources.
- SaaS
- Finished software you simply use (email, CRM, office suite); you manage almost nothing technical.
- Server
- A computer that delivers a service to many users continuously and reliably, built for availability.
- Share
- A folder or printer made available to other machines on the network.
- Shared responsibility
- The split of duties between provider and customer; security and data stay partly yours.
- SharePoint
- Shared organization-level storage, document libraries and intranet sites.
- Snapshot
- A saved state of a VM you can roll back to, useful for safe testing.
- Software licence
- The agreement granting the right to use a program under stated conditions.
- Specialization
- Focusing on a domain (networking, cloud, security, systems) after a generalist base.
- Standard vs administrator account
- A standard account can work day-to-day safely; an administrator account can change the whole system and should be used sparingly.
- Storage vs bandwidth
- Storage is measured in bytes (how much you can keep); bandwidth in bits per second (how fast data moves).
- Subnet mask
- A value (e.g. 255.255.255.0) that separates the network part from the host part — it defines who is on the same local network.
- Support
- The visible side of IT: helping users solve problems and keep working.
- Switch
- Connects devices within the local network, sending traffic only to the port that needs it.
- Symptom vs cause
- The symptom is what the user sees; the cause is the underlying reason. Fix the cause, not just the symptom.
- Teams
- The collaboration hub (chat, calls, meetings) that stores files in SharePoint and OneDrive.
- Test before scale
- Trying a command on one target or a copy before running it broadly.
- Ticket
- A logged record of a user request, tracked from creation to resolution.
- Ticketing system
- The tool that logs, prioritizes, tracks and closes tickets (e.g. a service desk).
- Tier 1 (Level 1)
- The first line of support, handling common issues and routing the rest.
- tracert / traceroute
- Command that shows the hop-by-hop path packets take to a destination, revealing where it stalls.
- Uptime / availability
- The share of time a service is actually usable; a core goal of IT because the business relies on it.
- User account
- A person's cloud identity, managed centrally rather than per device.
- Verb-Noun
- PowerShell's consistent command style (Get-, Set-, New-, Remove-) that makes commands readable.
- Virtual machine (VM)
- A software-based computer with its own OS and apps, isolated from others.
- Virtualization
- Running several independent virtual machines on one physical host.
- What changed
- The recent modification (update, device, setting) that most often explains a new problem.
- Windows
- Microsoft's OS, the standard on business desktops and laptops.
- Windows Update
- The service that keeps Windows patched and current; run it right after installing.
- Workstation
- A computer (desktop or laptop) that serves one user at a time.