Home Server Glossary: 40+ Self-Hosting Terms Explained for Beginners

Self-hosting comes with a lot of unfamiliar vocabulary, and most guides — including the other guides on this site — assume you already know it. This page is a plain-English reference for the terms you'll run into most often, grouped by topic so you can jump to what you need. Bookmark it and come back whenever a guide uses a word you don't recognize.

Core concepts

• Self-hosting — running software on hardware you own instead of paying a company to run it for you in the cloud. See our full is it worth it? breakdown.
• Homelab — the informal, community term for a personal setup of home servers and networking gear used for self-hosting and learning.
• Home server — any always-on computer in your house that runs services for your other devices. See our full explainer.
• Open source — software whose underlying code is publicly viewable and often free to use and modify, as opposed to closed, proprietary software.
• Uptime — how much of the time a service stays running and reachable, usually expressed as a percentage.

Hardware & storage

• NAS (Network-Attached Storage) — a dedicated device built specifically for storing and serving files over your network, often with multiple drive bays.
• Mini PC — a small-form-factor desktop computer, popular as budget home server hardware. See our mini PC buying guide.
• SBC (single-board computer) — a complete, tiny computer on one circuit board, such as a Raspberry Pi, often used for lightweight always-on tasks.
• HDD (hard disk drive) — a mechanical spinning-platter drive, cheaper per terabyte than SSDs and the standard choice for bulk media/photo storage.
• SSD (solid-state drive) — a drive with no moving parts, faster than an HDD, commonly used for the operating system or app data rather than bulk storage.
• RAID — a method of combining multiple drives so data survives if one drive fails, or so storage is pooled together as one larger volume.
• Bit rot — the slow, silent corruption of stored data over time; modern filesystems like ZFS can detect and often repair it automatically.
• Drive bay — a physical slot in a NAS or server case designed to hold one storage drive.
• UPS (uninterruptible power supply) — a battery backup that keeps a server running briefly during a power outage, protecting against data corruption from sudden shutdowns.

Operating systems & virtualization

• Hypervisor — software that lets one physical machine run several separate virtual machines at once, each isolated from the others.
• Virtual machine (VM) — a fully simulated computer running inside your physical machine, with its own operating system, isolated from the host.
• Container — a lighter-weight way to isolate an app than a full VM; it shares the host's operating system kernel but keeps the app and its files separate. See our Docker explainer.
• Bare metal — software installed directly on physical hardware, with no virtualization layer in between.
• Proxmox VE — a free, open-source hypervisor OS that turns one machine into a mini data center of VMs and containers. See our OS comparison.
• TrueNAS — a free, storage-first server OS built around the ZFS filesystem, with apps layered on top.
• Unraid — a paid, beginner-friendly server OS known for flexible storage pooling and an easy app store.
• ISO (image) — a single file containing the complete contents of an installer disc, used to install an operating system onto new hardware.

Software & apps

• Docker — the packaging system most self-hosted apps use to bundle software with everything it needs to run. See our full Docker for Beginners guide.
• Docker Compose — a configuration file format for describing and launching one or more Docker containers at once, with their settings, in a single command.
• Image (Docker image) — the downloadable, read-only template a container is created from — think of it as a frozen blueprint of an app.
• Portainer — a web-based dashboard for managing Docker containers without typing commands in a terminal.
• Reverse proxy — a piece of software that sits in front of your self-hosted apps and routes web traffic to the right one, often also handling HTTPS certificates.
• Web UI / dashboard — the browser-based control panel most self-hosted apps provide, so you rarely need direct command-line access.
• The *arr stack — a nickname for tools like Sonarr and Radarr that automatically find, download, and organize media files for a server like Jellyfin or Plex.

Networking

• LAN (local area network) — the private network inside your home connecting your devices to your router and to each other.
• WAN (wide area network) — the public internet, outside your home network, on the other side of your router.
• IP address — the numeric address a device uses to identify itself on a network.
• Static IP — an IP address that's manually fixed rather than automatically reassigned, important for a server so its address doesn't change unexpectedly.
• DNS (Domain Name System) — the system that translates human-readable names (like a website address) into numeric IP addresses.
• DHCP — the protocol your router uses to automatically assign IP addresses to devices as they join the network.
• Port forwarding — a router setting that allows outside internet traffic to reach a specific service on your home network; generally best avoided in favor of a VPN.
• VPN (virtual private network) — an encrypted tunnel that lets you securely reach your home network's services from outside, without exposing them directly to the internet.
• VLAN — a way of splitting one physical network into multiple isolated logical networks, often used to separate a homelab from everyday devices.

Security & backup

• Firewall — software or hardware that blocks unwanted network traffic based on a set of rules, a basic layer of protection for any server.
• SSL/TLS certificate — the digital certificate that enables the padlock/HTTPS icon in a browser, encrypting traffic between you and a service.
• 3-2-1 backup rule — a backup principle: keep 3 copies of your data, on 2 different types of storage, with 1 copy stored somewhere off-site.
• Snapshot — a point-in-time copy of a system or drive's state, letting you roll back changes if something breaks.
• Redundancy — having duplicate hardware or data copies so a single failure doesn't cause data loss or downtime.
• Tailscale — a popular, beginner-friendly VPN tool that makes secure remote access to a home server simple to set up.

Still confused by a term?

If you run into a word on this site that isn't listed here, the article that uses it usually links straight to a fuller explanation the first time it appears — that's intentional, so you're never expected to already know the jargon. Start with What Is a Home Server? if you're brand new, or Docker for Beginners if containers and images are the part that's confusing.