AI Learning Hub
beginner

Glossary & milestone quiz

One-screen recap, then ten questions. Pass with ≥7/10 to call yourself fluent in the foundations.

The whole track in one picture

Every lesson in the track maps to one stage of this end-to-end loop.

Acronym cheat sheet

The tech world loves three-letter labels. Here are the ones you've met (and a few you'll meet next), each tied to its meaning so the letters stop being random.

AcronymFull formHow to remember
AIArtificial IntelligenceMachines doing things that needed human intelligence.
MLMachine LearningPrograms that learn from examples, not from rules.
LLMLarge Language ModelLarge (huge) + Language (text) + Model (a learned program).
BPEByte-Pair EncodingCommon pairs of bytes (characters) get bundled into single tokens.
APIApplication Programming InterfaceThe "front desk" one Application uses to ask another for something.
JSONJavaScript Object NotationText with curly braces. Universal data format on the web.
TTFTTime To First TokenThe pause before the very First Token appears.
TPSTokens Per SecondHow fast text streams once it's started.
RAGRetrieval-Augmented GenerationRetrieve the right passage → Augment the prompt with it → Generate the answer.
CoTChain-of-ThoughtIntermediate thinking steps before the final answer. "Think step by step."
RLHFReinforcement Learning from Human FeedbackRL (rewarding good behaviour) + HF (rewards come from humans rating responses).
MCPModel Context ProtocolA protocol for giving any Model the right Context from any source. "USB-C for AI tools."
PIIPersonally Identifiable InformationAny info that identifies a person — name, email, ID.
OCROptical Character RecognitionOptically reading characters (text) inside images.
GPUGraphics Processing UnitThe chip type that powers AI training and inference.

(Hover any acronym anywhere in the lessons to see its full form and memory hook.)

Plain-English glossary

TermIf you only remember one thing…
LLMA very, very good autocomplete.
TokenThe chunks of text the model bills by. ~0.75 words per token in English.
Context windowThe chef's counter. Everything in this conversation has to fit on it.
System promptThe manager's brief — your rules and persona, set by the developer.
User / AssistantThe customer's question / what the assistant said earlier.
TemperatureDice heat. 0 = always favourite. Higher = more variety.
Top-pRoll the dice only among the top X% of probability mass.
HallucinationConfident-sounding text that's plain wrong.
TTFTThe pause before the model starts speaking. The thing users feel.
StreamingSpeaking while still thinking — same total time, much better UX.
Prompt cachingThe translator memorising the briefing instead of re-reading it.
Model routingCheap translator for easy questions, senior interpreter for hard ones.
RAG (medium track)Giving the model the actual document instead of asking from memory.
Embedding (medium track)A vector that captures meaning — used for semantic search.
Tool calling (medium track)The model asks your code to run a function; reads the result; replies.
Agent (medium track)An LLM in a while loop that can call tools.
Fine-tuning (advanced)Continued training to specialise a model.

Cheat sheet: what to reach for

A user asks a question →
├── Generic knowledge → just call the LLM (low temperature, good system prompt)
├── Needs your data → RAG (medium track)
├── Needs an action → tool calling (medium track)
├── Needs many steps → agent loop (medium track)
└── Custom voice or rare task → fine-tuning (advanced track)

Milestone quiz (10 questions)

Check your understanding

  1. 1. Roughly how many tokens are in 1,500 words of English prose?
  2. 2. Which roles can the developer set in a chat request?
  3. 3. You set temperature=0 and run the same prompt twice. Will the outputs match?
  4. 4. Stuffing 199k tokens into a 200k context window — what's the most likely problem?
  5. 5. Output tokens are typically priced about how much higher than input tokens?
  6. 6. Your model returns a citation to 'Smith v. Jones, 412 F.3d 891 (4th Cir. 2009)'. Best next step?
  7. 7. Which of these is NOT a real way to reduce hallucinations?
  8. 8. Which is most likely a single token in a modern BPE tokenizer?
  9. 9. What's the strongest combination for a chatbot that should never invent facts?
  10. 10. You move from a frontier model to a mid-tier model — CSAT drops 2 points but cost drops 80%. The right framing?

What's next

You're ready for the Medium track, where you'll learn how production LLM apps are actually built: embeddings, RAG, prompt engineering, tool calling, agents, evals, and caching. Things start to feel less like magic and more like systems.

Related lessons in this track