AI/ML2025-11-3012 min readBy Abhishek Nair

Agentic AI for Dummies, Part 1: What Actually IS an AI Agent?

#Agentic AI#AI Agents#ReAct#Memory Systems#Chatbots#Machine Learning#LLMs#Autonomous Systems#AI
Loading...

Agentic AI for Dummies, Part 1: What Actually IS an AI Agent?

The Complete Beginner's Guide to Understanding AI That Does Things, Not Just Says Things

Reading time: 12 minutes | Difficulty: Beginner-friendly


You've probably used ChatGPT or Claude. You type something, it types back. Simple, right?

But here's the thing — that's not really the future of AI. That's just the beginning.

The real revolution happening right now is something called Agentic AI — AI that doesn't just talk about doing things, but actually does them. AI that can book your flights, analyze your data, fix your code, and manage projects — all while you grab a coffee.

In this series, we're going to break down everything about agentic AI in a way that actually makes sense. No PhD required. If you can follow a recipe, you can understand this.

Let's dive in.


🤖 The Big Idea

What's the Difference Between a Chatbot and an AI Agent?

Here's the simplest way to think about it:

A chatbot is like a vending machine. You press a button, you get exactly that item.

An AI agent is like a personal chef. It understands your tastes, sources ingredients, adapts recipes, and learns what you like over time.

Loading...

Let me make this concrete with an example.

You ask: "Book me a flight to Tokyo"

Chatbot ResponseAI Agent Response
"Here's how to book flights: 1. Go to a travel website, 2. Enter your dates..."Actually searches flightsCompares pricesChecks your calendarBooks the optimal flightAdds confirmation to your travel folder
❌ Describes the process✅ Actually completes the task

See the difference? One talks about doing things. The other does them.

The Six Superpowers That Make an Agent an "Agent"

What transforms a regular AI into an agent? Six key characteristics:

  1. Autonomy — Works toward goals without you hovering over it
  2. Reasoning — Thinks through problems and makes decisions
  3. Adaptable Planning — Changes course when things don't go as expected
  4. Context Understanding — Gets what you actually mean, not just what you say
  5. Action-Taking — Actually does things in the real world
  6. Persistence — Remembers and learns across conversations

If your AI has all six, congratulations — you've got an agent.


🔄 The Agent Loop: How AI Agents Actually Work

Every AI agent runs on the same basic cycle. It's called the Perceive-Reason-Act-Learn loop, and once you understand it, you'll understand how every agent works.

Loading...

Here's what happens at each step:

👁️ Step 1: PERCEIVE

The agent takes in information from its environment:

  • What you just said or typed
  • Results from its last action
  • Data from APIs it's connected to
  • Feedback about whether things worked

Think of it like: Opening your eyes and ears to understand the current situation.

🧠 Step 2: REASON

This is the brain. The agent:

  • Accesses its memory and knowledge
  • Thinks about the goal
  • Weighs different options
  • Decides what to do next

Think of it like: That moment when you pause and think "okay, what's the best move here?"

⚡ Step 3: ACT

The agent takes action:

  • Calls an API
  • Runs some code
  • Sends a message
  • Searches the web
  • Saves a file

Think of it like: Actually doing the thing, not just thinking about it.

📚 Step 4: LEARN

The agent updates itself based on what happened:

  • Did that work?
  • What should I remember for next time?
  • How does this change my approach?

Think of it like: The mental note you make after trying something new.

Then the cycle repeats. Again and again until the goal is achieved.

Key insight: Unlike a chatbot that stops after one response, this loop runs continuously. The agent keeps perceiving, reasoning, acting, and learning until the job is done.


🧪 ReAct: The Breakthrough That Made Agents Smart

In 2022, researchers at Google made a breakthrough. They figured out that if you let AI alternate between thinking out loud and taking action, it gets dramatically better at complex tasks.

They called it ReAct (Reasoning + Acting).

Loading...

Let's walk through a real example:

You ask: "Who has won more Grammys — Taylor Swift or Beyoncé?"

Without ReAct, the AI might just guess based on what it learned during training. Often wrong, often outdated.

With ReAct, here's what happens:

StepWhat the Agent Does
💭 THOUGHT #1"I need Grammy counts for both artists. Let me search for Taylor first."
ACTION #1Searches: "Taylor Swift Grammy wins"
👁️ OBSERVATION #1"Taylor Swift has won 14 Grammy Awards"
💭 THOUGHT #2"Got it. Now I need Beyoncé's count."
ACTION #2Searches: "Beyoncé Grammy wins"
👁️ OBSERVATION #2"Beyoncé has won 32 Grammy Awards"
💭 THOUGHT #3"32 is greater than 14. I can answer now."
ANSWER"Beyoncé has won more Grammys (32) compared to Taylor Swift (14)."

Why does this matter?

Before ReAct:

  • AI that only reasons (like Chain-of-Thought) often hallucinates facts — it can't verify anything
  • AI that only acts executes blindly without strategic planning

ReAct combines the best of both:

  • The thinking makes decisions interpretable (you can see why it did something)
  • The actions ground the AI in reality (it verifies instead of guesses)

The results speak for themselves: ReAct achieves 34% better success rates on complex tasks compared to approaches that only reason or only act.


🧠 How AI Agents Remember: The Memory Systems

Here's something that surprises people: regular chatbots have amnesia. Every conversation starts fresh. They don't remember that you told them your name yesterday, or that you prefer morning meetings, or that you're vegetarian.

AI agents are different. They have memory systems — and these are what make them actually useful over time.

Loading...

Just like humans, agents have two main types of memory:

⚡ Short-Term (Working) Memory

This is what the agent is thinking about right now:

  • The current conversation
  • Recent actions and their results
  • Where we are in solving the current problem

Key point: This resets when the conversation ends.

💾 Long-Term Memory

This persists forever. It's stored in databases and retrieved when needed.

Long-term memory has three subtypes (just like human memory!):

TypeWhat It StoresExample
📸 EpisodicSpecific past events"User booked a trip to London last month"
📚 SemanticFacts and general knowledge"Flights to Tokyo take about 14 hours"
⚙️ ProceduralLearned skills and processes"User's preferred code review workflow"

Memory vs. RAG — What's the Difference?

  • RAG = Helps agents answer better by retrieving external facts (stateless fact-finding)
  • Memory = Helps agents behave smarter by remembering context and preferences (enables personalization)

Production agents typically need both.


📊 The Impact Is Already Real

This isn't theoretical. Agentic AI is already transforming how work gets done:

MetricImpact
126%Faster coding with GitHub Copilot
14%More customer inquiries handled per hour
80%Customer service issues resolved without humans (projected by 2029)
$7.92BCurrent agentic AI market size (2025)

🎯 Key Takeaways

  1. Agents ≠ Chatbots — Chatbots react to prompts. Agents pursue goals autonomously.

  2. The Agent Loop — Every agent runs on Perceive → Reason → Act → Learn, continuously until the goal is achieved.

  3. ReAct — The breakthrough pattern of alternating reasoning and action that makes agents dramatically better at complex tasks.

  4. Memory Systems — Short-term (current context) + Long-term (episodic, semantic, procedural) enable persistence and personalization.

  5. Real Value — Agents solve the core limitations of raw LLMs: grounding, tool use, verification, multi-step execution, and memory.


🔜 What's Next

Part 2: The framework ecosystem — LangChain, CrewAI, AutoGPT, and more Part 3: How agents use tools — function calling, APIs, and security Part 4: Real-world applications and the future trajectory


Series Navigation:

Last updated: December 2025

Abhishek Nair
Abhishek Nair
Robotics & AI Engineer
About & contact
Why trust this guide?

Follow Me