HotRaccoon Labs

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Welcome to the DevOps Lab

Learn how modern software gets built, deployed, and kept running — through animated visualisations of CI/CD pipelines, DNS lookups, load balancers, autoscalers, and more. No prior experience needed.

15 interactive modulesFrom vocabulary basics to TCP/IP, DNS, CI/CD, blue-green deploys, autoscaling, and WebSockets — all animated.

Watch real infrastructureSee packets flow through a server stack, watch a canary deployment roll out, and trigger an autoscaler under simulated load.

Plain English throughoutEvery concept explained before the jargon. Start with 'Words to know' — a glossary of 20 DevOps terms in one sentence each.

Guided Path0/15 done

Foundations · Vocabulary

Common Words (Read First)

Every field has jargon. Before any other lesson, here are the 20 words that come up everywhere in DevOps — explained in plain English. The Glossary panel on the right has the full definitions.

ELI5

When you start cooking, you learn what 'sauté' and 'simmer' mean before recipes make sense. Same here. Words like 'packet', 'cache', 'endpoint', 'protocol' will appear constantly. You don't need to memorize them — just glance through this list once. They'll click as you see them in the animated lessons that follow.

How it works

Each card on the canvas shows a term + a quick one-line meaning. The full definitions are in the Glossary panel on the right (open by default). Skim once; come back when you need to.

Glossary

client: The thing asking for something — usually your laptop, phone, or browser. Opposite of 'server.'
server: An always-on computer waiting to answer requests. Lives in a data center. When someone says 'the server is down,' they mean one of these stopped responding.
browser: The program (Chrome, Safari, Firefox) you use to open web pages. It's a 'client' that speaks HTTP.
request: A message sent from client to server saying 'please give me X' or 'please save this.' Every action you take on a website is a request.
response: The server's reply to a request. Usually contains the page, image, or data you asked for, plus a status code (200 = success, 404 = not found, 500 = server error).
packet: A tiny chunk of data — the unit computers actually send across the internet. A request gets chopped into many packets, sent across the network, and reassembled on the other side. You almost never think about packets directly; they're the rivets.
protocol: The agreed-upon rules two computers follow to talk. 'HTTP' is a protocol. 'TCP' is a protocol. Like 'always say hello before talking' but for machines.
HTTP: Hyper Text Transfer Protocol. The protocol web browsers and servers use to send pages, images, and JSON. The most-used protocol on the internet.
HTTPS: HTTP, but encrypted with TLS. Adds a padlock to the URL bar. Anyone snooping the wire sees gibberish instead of your password.
URL: Uniform Resource Locator. A web address. `https://hotraccoon.com/labs/devops` is a URL — protocol + domain + path.
IP address: A computer's numeric address on the internet, like `142.250.80.46`. DNS translates names (google.com) to IPs so packets know where to go.
port: A numbered door on a server. Each service listens on a port: HTTP uses 80, HTTPS uses 443, SSH uses 22. A URL like `localhost:3000` means port 3000.
cache: A saved-for-later copy of something expensive. The first request fetches it; later ones get the cached copy instantly. Browsers cache images; CDNs cache web pages; DNS caches lookups. Cache hits are why the web feels fast.
API: Application Programming Interface. A way for code to talk to other code. When you 'call the Stripe API,' you're sending an HTTP request to Stripe's server and reading the response.
endpoint: One specific URL your app responds at. `/login`, `/users/123`, `/api/checkout` — each is an endpoint. APIs are collections of endpoints.
payload: The actual data inside a request or response. For a 'create user' request, the payload would be `{ name: 'Aaron', email: '...' }`.
database: A program (Postgres, MySQL, MongoDB, etc.) that stores your app's lasting data — user accounts, posts, orders. The app server talks to the database; the database is rarely exposed to the public internet.
deploy: To put new code on the live server so real users see it. 'I'll deploy after lunch' = 'I'll push my changes to production after lunch.'
latency: How long one request takes, end to end. 'Latency was 200ms' = the user waited 200 milliseconds for a response. Lower is better.
bandwidth: How much data fits through the pipe per second. Different from latency: a satellite link can have huge bandwidth but huge latency.

Where this shows up

📖
Open the Glossary panel →
Every other lesson in this lab also has its own glossary in the sidebar — open it whenever a word stumps you.
🛠️
Browser DevTools Network tab
Open any website, hit F12, click Network. Every row is one request, with its URL, status, latency. The vocabulary above stops being abstract the moment you start clicking around in there.
📚
MDN Web Docs
developer.mozilla.org — the canonical reference for every web term. Bookmark it.

Furniture takeaway

The best way to learn DevOps vocabulary isn't to memorize it — it's to recognize it when you see it. Skim this once. As you move through the next 13 lessons, you'll meet each word in context with a visual. By the end, they'll feel obvious.

Pro tip: every other module also has its own Glossary section in the sidebar — open it whenever a word stumps you. You won't need to remember everything; just know where to look.