Homelab Glossary — Build a Homelab

A

#Arr stack: The family of media-automation apps whose names end in "-arr": Sonarr, Radarr, and Prowlarr. Together they watch for the shows and movies you want, find them, and hand them to your media server automatically.

B

#Bind mount: A way of making a folder that lives on the host machine appear inside a container. Unlike a named volume, you choose exactly which host folder is shared — which makes your data easy to find and back up.
#Bridge (network): A virtual switch inside your server that connects VMs and containers to your real network. Proxmox's default bridge, vmbr0, is why a fresh container can grab an IP address from your router as if it were a physical machine.

C

#Cloud-init: A small tool baked into many Linux images that configures a fresh VM on first boot — hostname, user, SSH keys, network. It's what turns "clone a template" into "clone a template and have it ready in ten seconds."
#Cluster: Two or more servers managed as one unit. In a Proxmox cluster you log into any node and see them all, migrate workloads between them, and survive a single machine dying.
#Container: A lightweight, isolated environment that shares the host machine's kernel instead of booting its own operating system. Containers start in seconds and use a fraction of the memory a VM needs — the trade-off is less isolation.
#Corosync: The messaging layer Proxmox cluster nodes use to stay in constant agreement about who is alive and who holds which workload. It is latency-sensitive, which is why cluster guides insist on a wired network.

D

#DHCP: The protocol your router uses to hand out IP addresses automatically. Convenient for laptops and phones; for servers you usually want a static IP instead, so the address never changes underneath you.
#Direct play: When your media server sends a video file to your TV untouched, because the TV can already decode it. This is the goal state: near-zero CPU cost, perfect quality, no waiting.
#DNS: The internet's phone book — it turns names like buildahomelab.dev into IP addresses. Run your own resolver (like Pi-hole) and you control the phone book: ad domains can simply stop existing.
#Docker: The most popular way to run containers. You describe what an app needs, Docker fetches a ready-made image, and the app runs the same way on any machine — no more "works on my box."
#Docker Compose: A YAML file that describes a whole group of containers — services, networks, volumes — so you can start or stop the entire stack with one command. Your first Compose stack is a rite of passage.

E

#Exit node: A Tailscale device that routes all your traffic through itself, not just traffic to your homelab. Turn your home server into an exit node and coffee-shop Wi-Fi sees only encrypted noise.

F

#Firewall: A filter that decides which network traffic is allowed in or out. The homelab habit worth building early: deny by default, then open only what you actually use — Proxmox has this built in.

G

#GPU passthrough: Handing a physical graphics card directly to one VM so it gets native performance — used for video transcoding and local AI. Requires IOMMU support and a little BIOS spelunking.
#Grafana: The dashboard layer of the monitoring world. It doesn't collect anything itself — it turns the numbers Prometheus stores into graphs you'll actually look at.

H

#Hardlink: Two directory entries pointing at the same file data, so a "copy" costs zero extra disk space. The arr stack uses hardlinks so your download folder and media library can both "contain" a file that exists on disk only once.
#High availability (HA): Configuring a cluster so that when a node dies, its workloads restart automatically on a surviving node. Needs shared storage and quorum — and it's the reason three nodes beat two.
#Homelab: A server (or several) you run at home to host your own services and learn by doing. The wonderful rabbit hole this whole site is about.
#Hypervisor: Software that slices one physical machine into many virtual ones. Proxmox VE is the homelab favourite: free, web-managed, and equally happy running VMs and containers.

I

#IOMMU: A CPU/motherboard feature that lets the system hand a real PCI device (like a GPU) safely to a virtual machine. It's the hardware prerequisite for GPU passthrough; enable it in the BIOS.
#ISO image: A single file containing the full contents of an installer disc. You write it to a USB stick (or let Ventoy hold a whole collection) and boot a machine from it to install an operating system.

J

#Jellyfin: A fully free, open-source media server — the DIY alternative to Plex. No accounts, no paywalls, every feature unlocked; you trade a little polish for complete ownership.

L

#Let's Encrypt: A free certificate authority that issues the TLS certificates behind the padlock icon. Paired with Traefik, your homelab services get real HTTPS that renews itself.
#LLM: Large language model — the kind of AI model behind ChatGPT and Claude. With Ollama you can run smaller open-weight LLMs entirely on your own hardware, no cloud account required.
#LXC: Linux system containers — a full Linux userland sharing the host's kernel. Proxmox uses LXC for its containers: most homelab services run beautifully in one at a fraction of a VM's cost.

M

#Metrics: Numbers about your systems captured over time — CPU load, disk space, temperatures. Collected by Prometheus, drawn by Grafana, and the difference between guessing and knowing.
#Mini PC: A palm-sized desktop (HP EliteDesk, Lenovo Tiny, Dell Micro) that sips power and sells cheap off corporate leases. The current best-value foundation for a quiet homelab.

N

#NAS: Network-attached storage — a box whose whole job is holding files and serving them over the network. Can be a commercial unit (Synology, QNAP) or a role your server plays.
#NAT: Network address translation — the trick your router uses to share one public internet address among every device in your house. It's also an accidental firewall: nothing outside can reach your machines unless you (or a tunnel like Tailscale) arrange it.
#NFS: The native file-sharing protocol of the Unix world. Faster and simpler than Samba between Linux machines; the usual choice for sharing storage to Proxmox nodes and containers.
#Node: One physical machine in a cluster. "The cluster lost a node" sounds dramatic, but with quorum and backups it's a Tuesday.

O

#Ollama: A tool that makes running local AI models one command: ollama run llama3.2. It manages downloads and serves an API other apps can use — even across a CPU-only cluster.

P

#Plex: The most polished self-hosted media server: your movies and shows in a Netflix-style interface on every device. Easy to start with, with some features behind the paid Plex Pass.
#Port: A numbered door on an IP address — one machine can host many services because each listens on its own port (SSH on 22, HTTPS on 443, Jellyfin on 8096). "Open a port" means letting traffic through that door.
#Port forwarding: Telling your router to pass outside traffic on a port through to a machine inside your network. Traditional but risky for remote access — a Tailscale tunnel gets you in without opening anything.
#Prometheus: The standard open-source metrics database: it scrapes numbers from your systems every few seconds and stores their history. Pairs with Grafana for dashboards — the classic homelab monitoring stack.
#Proxmox Backup Server: Proxmox's dedicated backup companion. It deduplicates aggressively — nightly backups of every container often add only megabytes — and verifies its own archives.
#Proxmox VE: The free, open-source hypervisor this site is largely built on. One web interface to create VMs and LXC containers, manage storage and backups, and cluster machines together — the complete guide starts here.

Q

#Quorum: The majority vote a cluster needs before it will make decisions. With three nodes, any two can carry on if one dies; with two nodes, neither is a majority alone — which is why two-node clusters need a tiebreaker.

R

#RAG: Retrieval-augmented generation — giving an AI model your documents to read before it answers, so it responds from your facts instead of its memory. The technique behind chatting with your own notes.
#RAID: Combining several disks so the failure of one doesn't lose data (and often to gain speed). Remember the mantra: RAID keeps you running through a disk failure — it is not a backup.
#Reverse proxy: A single front door for all your web services: it receives every request and routes each to the right app, handling HTTPS in one place. Traefik is the homelab favourite.

S

#Samba (SMB): The file-sharing protocol Windows speaks natively (Macs and Linux too). If you want a shared folder that every device in the house can open, Samba is how.
#Self-hosted: Running the software yourself instead of renting it as a cloud service — your photos on your Immich, your passwords in your Vaultwarden. More control and privacy, in exchange for being your own ops team.
#Snapshot: A frozen point-in-time picture of a VM, container, or filesystem you can roll back to instantly. Take one before every risky change; future-you will be grateful.
#SSH: Secure Shell — the encrypted remote terminal every Linux server speaks. Day one of any homelab: switch it from passwords to keys.
#SSH key: A cryptographic key pair that replaces passwords for SSH. The private half never leaves your laptop; the public half goes on the server. Unphishable, unguessable, and less typing.
#Static IP: An address you assign permanently instead of letting DHCP choose. Servers need one — half of homelab troubleshooting is discovering something's IP changed overnight.
#Subnet: A block of IP addresses that make up one network — like 10.0.0.0/24, which spans 10.0.0.1 through 10.0.0.254. Devices on the same subnet talk directly; crossing subnets takes a router.
#Subnet router: A Tailscale device that advertises your whole home subnet to your other devices, so your phone can reach every service in the lab while only one machine runs Tailscale. The single best homelab upgrade per minute of effort.

T

#Tailscale: A zero-config VPN that puts your devices on a private encrypted network wherever they are — no port forwarding, no public exposure. The safest way to reach your homelab from anywhere.
#TDP: Thermal design power — a chip's designed heat output in watts, and a rough proxy for how much power it draws under load. For an always-on homelab, a low-TDP chip is money in your pocket every month.
#Template: A VM or container image you clone instead of installing from scratch. Build it once with your users, keys, and tools baked in; every future machine is ready in seconds.
#TLS / SSL: The encryption behind HTTPS and the browser padlock. Certificates prove a site is who it claims to be; Let's Encrypt hands them out free.
#Transcoding: Your media server converting video on the fly because the target device can't play the original format. CPU-expensive — which is why avoiding it or doing it in hardware matters on small machines.

U

#Uptime Kuma: A beautifully simple self-hosted monitor: it pings your services and tells you the moment one goes down. The right first monitoring tool — long before you need Grafana.

V

#Virtual machine (VM): A complete emulated computer — its own kernel, own OS, booting from its own virtual disk. Heavier than a container, but the right tool when you need full isolation or a different OS.
#VLAN: A virtual LAN — slicing one physical network into isolated segments, so your IoT gadgets can't see your NAS. Needs a managed switch, and it's the tidy way to grow a network.
#Volume: Docker-managed persistent storage that outlives the container using it. Containers are disposable; volumes are where the data you care about actually lives.
#VPN: An encrypted tunnel between machines across the internet. Two homelab uses: reaching your lab securely from outside (Tailscale), and hiding outbound traffic (a commercial provider in front of a download client).

W

#WireGuard: The modern VPN protocol — small, fast, and built into the Linux kernel. Tailscale is built on it; you can also run it raw if you enjoy managing keys by hand.

Z

#ZFS: A filesystem that checksums every block, self-heals with mirrored disks, snapshots instantly, and compresses transparently. Worth understanding before you commit a storage layout.