Servers come with a mountain of jargon. Here's every term this course uses, defined simply, often with a real-life comparison. Bookmark this page — you'll come back to it.
A
- A record
- A line in the internet's phone book (DNS) that says "this name belongs to this server's number." You add an A record to point your domain, like
example.com, at your server's IP address. (Module 8) - Anthropic
- The company that makes Claude. You sign up for an Anthropic account so Claude Code can log in as you. (Module 0)
- apt
- The "app store" for an Ubuntu server. You type
apt installto add software andapt upgradeto update it. (Modules 4–5)
B
- Backup
- A saved copy of your data or whole server, kept so you can restore it if something goes wrong. Some providers make automatic backups for a small fee. (Module 9)
- Bandwidth (transfer)
- How much data your site can send to visitors each month. Think of it like a monthly data allowance on a phone plan. Beginners rarely come close to the limit. (Module 1)
- Billing alert
- A setting that emails you before your spending grows past an amount you choose — your early-warning system against surprise bills. (Module 2)
C
- Caddy
- A modern web server that sits in front of your app and automatically turns on free HTTPS (the padlock). The beginner-friendly way to make a site secure. (Module 8)
- Certificate (HTTPS/SSL/TLS)
- A digital ID card that proves your site is really yours and switches on the padlock and encryption. It's free from Let's Encrypt, and Caddy fetches and renews it for you. (Module 8)
- CI/CD
- Short for Continuous Integration / Continuous Delivery — a robot assistant that automatically builds, tests, and ships your code every time you change it. A "next step" topic. (Module 10)
- Claude Code
- A version of Claude that runs in your terminal. It can read and write files and run commands (with your permission) so you can build software by describing what you want in plain English. (Module 6)
- Cloud
- A catch-all name for renting computing power from giant providers like AWS or Google Cloud. A VPS is really a simple, friendly corner of the cloud. (Module 1)
- Command line / terminal
- A text window where you type commands to control a computer, instead of clicking buttons. It looks intimidating but it's just typing. (Module 3)
- Commit
- A saved snapshot of your code at one moment, made with git — like a save point in a video game you can return to. (Module 5)
- curl
- A command that fetches a web page as plain text, right from the terminal. Handy for checking that your app is responding before it's public. (Module 7)
D
- Data center
- A big, secure building full of computers with fast internet and backup power. Your rented server physically lives inside one. (Module 1)
- Deploy
- To put your finished code onto the server where the public can reach it. "Shipping" it. (Modules 6, 10)
- DNS
- The Domain Name System — the internet's phone book. It turns a friendly name like
example.cominto the server's numeric IP address. (Module 8) - Domain
- Your website's human-friendly name, like
yourname.com, that people type into a browser. You buy one from a registrar. (Module 8)
E
- Environment variable / .env file
- A safe place to store secret settings — like passwords or API keys — outside your code, in a separate
.envfile that you never share or upload. (Modules 7, 10)
F
- Firewall
- A guard that blocks every network "door" (port) on your server except the few you choose to open. On Ubuntu we use a simple one called
ufw. (Module 4)
G
- git
- A time machine for your files. It tracks every version of your code so you can save progress and undo mistakes. Claude often uses it for you. (Module 5)
H
- HTML
- The basic language of web pages — the text that tells a browser what to show. Your first project may be plain HTML. (Module 7)
- HTTP / HTTPS
- The rules browsers use to load web pages. HTTPS is the secure, locked-up version — the padlock in the address bar means nobody can snoop on what's sent. (Modules 0, 8)
I
- IP address
- Your server's phone number on the internet — a string of numbers like
203.0.113.45. You connect to it and point your domain at it. (Modules 2–3)
L
- Let's Encrypt
- A free service that hands out HTTPS certificates so any site can have the padlock at no cost. Caddy uses it automatically. (Module 8)
- localhost
- A computer's nickname for itself.
http://localhost:3000means "the app running right here on this same machine." (Module 7) - Logs
- A running diary of what a program did. The first place to look when something breaks — it usually tells you exactly what went wrong. (Module 9)
- LTS
- Long-Term Support — a version (of Ubuntu, or of Node.js) that gets updates and fixes for years. The stable, boring, beginner-friendly choice. (Modules 2, 5)
N
- Nginx
- A classic, powerful web server often placed in front of an app as a reverse proxy. Does the same job as Caddy but with more manual steps for HTTPS. (Module 8)
- Node.js
- An engine that lets a server run JavaScript programs. Claude Code needs it, and many small apps are built on it. (Module 5)
- npm
- Node's built-in installer for add-on code packages. It comes bundled with Node.js. (Module 5)
- nvm
- Node Version Manager — the friendly way to install and upgrade Node.js without admin headaches or permission errors. (Module 5)
P
- Package manager
- A tool that installs and updates software for you.
aptis the server's;npmis Node's. Like an app store you drive by typing. (Module 5) - pm2
- A process manager that keeps your app running, restarts it if it crashes, and starts it again after a reboot. (Module 9)
- Port
- A numbered door on a server where a program listens for visitors. Port 80 = web, 443 = secure web, 22 = SSH, 3000 = a common spot for a new app. (Modules 4, 7)
- Private key / Public key
- The two halves of an SSH key pair. The public key is a lock you put on the server (safe to share). The private key is the only key that opens it (keep it secret, always). (Module 3)
- Process manager
- A program whose job is to babysit your app — keeping it alive, restarting it after crashes and reboots. We use pm2. (Module 9)
- Propagation
- The short wait (minutes to a few hours) while a DNS change spreads across the internet so everyone can find your domain. (Module 8)
R
- RAM
- A computer's short-term memory — the desk space it uses while programs are running. More RAM means more can happen at once. 1 GB is plenty to start. (Module 1)
- Registrar
- A company that sells domain names, like Namecheap, Cloudflare, or Porkbun. (Module 8)
- Region
- Which city or country your server lives in. Pick one near your visitors so your site feels fast. (Module 2)
- Reverse proxy
- A program that sits at the front desk, greets every visitor on ports 80/443, quietly passes them to your app, and handles the HTTPS padlock. Caddy and Nginx do this. (Module 8)
- root
- The all-powerful main administrator account on a server. Because it can do anything, we stop using it day-to-day and make a safer normal user instead. (Modules 3–4)
S
- Server
- A computer whose job is to stay on and answer requests from the internet — like handing out web pages when someone visits your site. (Module 1)
- Shared hosting
- The cheapest, most limited way to host a site: you share one computer with many others and can't install your own tools. Fine for simple sites, too restrictive for this course. (Module 1)
- Snapshot
- A photograph of your entire server at a moment in time. If something breaks, you can restore from it. Take one before big changes. (Module 9)
- SSD / Storage
- The server's long-term "closet" where files live even when it's powered off. 25 GB is roomy for a first project. (Module 1)
- SSH
- Secure Shell — an encrypted, private tunnel that lets you type commands on your server from your own computer. The front door to your machine. (Module 3)
- SSH key (key pair)
- Two matching files that prove who you are without a password: a public key on the server and a secret private key on your computer. Safer than a password. (Module 3)
- sudo
- Short for "do this as the administrator." You put
sudoin front of a command when it needs extra power to run. (Module 4) - systemd
- Linux's built-in manager for starting, stopping, and auto-restarting programs (called "services"). A more advanced alternative to pm2. (Module 9)
T
- Terminal
- See Command line. The text window where you type commands. (Module 3)
U
- Ubuntu
- The most popular, beginner-friendly version of Linux for servers. We pick the "LTS" edition for stability. (Module 2)
- ufw
- "Uncomplicated Firewall" — the simple firewall tool on Ubuntu you use to open only the ports you need. (Module 4)
V
- vCPU
- A virtual CPU — your share of the server's "brain" (its processor). One is plenty for a first project. (Module 1)
- VPS
- Virtual Private Server — your own private "apartment" inside one big shared computer in a data center. You rent it, control it fully, and it stays on 24/7. The heart of this course. (Module 1)
W
- Working directory
- The folder you're currently "inside" in the terminal. Commands act on this folder unless you say otherwise. (Module 5)
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Still stuck on a word?
If a term isn't here, it probably appears with its own plain-English explanation the first time it's used inside a module. Head back to the course path and use the Modules menu to find it.