Station 1 · AI Agents 101
A chatbot answers your question and stops. An agent takes a goal and keeps working — planning, using tools, and checking its own results — until the job is actually done.
What you'll walk away with
Concept 1
You've used a chatbot: you type, it replies, done. That's one turn. An agent is what you get when you let the model take actions and keep going toward a goal.
One question in, one answer out. It can only use what it already "knows." If it's unsure, it guesses.
Given a goal, it plans steps, uses tools to get real information, checks the result, and loops until it's done.
A chatbot is someone who can recite a recipe. An agent is a chef: they read the goal ("make dinner"), grab tools (knife, stove), taste as they go, fix the seasoning, and don't stop until the meal is on the plate. Same knowledge — but one of them actually cooks.
Concept 2
On its own, an LLM can only produce text. A tool is an ability you hand it — a function it can choose to call — that lets it reach outside itself.
An agent = an LLM + tools + a loop. The LLM is the brain, tools are the hands, and the loop is what keeps it going until the goal is met.
Concept 3
Here's the same request handled two ways. Notice the agent doesn't guess — it uses a tool to find out.
# You ask: "What's the weather in Austin right now, and should I bike?" # CHATBOT (no tools): "I can't know live weather, but Austin is usually warm..." # a guess # AGENT (has a weather tool): Thought → "I need live weather. Call the tool." Action → get_weather("Austin, TX") Observe → 41°F, raining Answer → "It's 41°F and raining — maybe skip the bike today."
Concept 4
Straight from the real-world map — agents show up wherever a task needs more than one step:
Book things, draft replies, manage a to-do list across apps.
Read a codebase, write & edit files, run tests, fix errors (Cursor, Claude Code).
Load a dataset, run queries, make charts, explain findings.
Search, read pages, and summarize across many sources.
Every one of these is the same recipe — an LLM using tools in a loop. The rest of this roadmap unpacks each piece: the loop (Station 3), tools (Station 4), memory (Station 6), and more.
Checkpoint
A friend says "ChatGPT is an AI agent." When is that most accurate?
A plain chat turn is just an LLM answering. It becomes an agent when it's given tools and a loop so it can act, observe, and keep going toward a goal. (Modern ChatGPT can do this when it browses or runs code — that's the agent mode.)
See it yourself — 5 minutes
Open any AI chatbot that can browse the web or run code (ChatGPT, Gemini, or Claude) and try this:
Recap. A chatbot talks; an agent acts. The magic ingredient is tools — abilities the LLM can call — run inside a loop until the goal is met. Next, let's look at the engine all of this runs on: the LLM itself.