LESSON 02 / 215·2 min readFoundation

Priority key

ReferenceReference guide
01 Understand02 Recall03 Prepare

Words made simple

A few useful meanings before you read the explanation.

API
A way for one piece of software to ask another for data or an action. A claims API might return the current status of a claim.
LLM
A model trained to work with language. It can write or summarize text, but its answer still needs checking against reliable information.
Embedding
A list of numbers that represents the meaning of some content. Similar meanings can produce nearby lists of numbers.
More words from this lesson
Vector
An ordered list of numbers. An embedding is a vector used to represent content for tasks such as similarity search.
RAG
Find relevant information first, then give it to a model to help answer the question. The answer is only as reliable as the information and checks used.
Structured output
An answer organized into specified fields, such as claimId and status, instead of only free-form text.
Tool calling
The model proposes using a named function and supplies its inputs. Application code checks permissions and runs the function.
Agent
An application that uses a model to choose its next action within defined limits. It can use tools and continue through several steps.
PriorityTopics
🔴 MUST KNOWLLM APIs, prompting, structured outputs, tool calling, embeddings, vector search, RAG, LangChain, LangGraph, agents, MCP, Python basics, FastAPI, MERN integration, security, guardrails, evaluation, observability
🟠 SHOULD KNOWMicrosoft Agent Framework, OpenAI Agents SDK, multi-agent systems, orchestration, Temporal, Redis/BullMQ, memory, hybrid search, reranking, agentic RAG, gateways, routing, cost optimization
🟡 GOOD TO KNOWMultimodal applications, voice agents, local LLMs, Ollama, Hugging Face
🟢 ADVANCEDFine-tuning, LoRA, QLoRA, vLLM, GPU optimization
PAUSE & RECALL

Can you explain it without the notes?

Priority key

Use your own words. Explain an example and one limitation before checking the explanation.

Check your explanation

Priority key

CONNECT IT TO YOUR INTERVIEW

Turn this concept into a clear answer.

Practice this concept
YOUR NEXT STEP

Keep connecting the ideas.

Next lesson: Contents

Adapted from 13_AI.MD · “Priority key”. Examples are study fragments; framework behavior can depend on your version.