Artificial agents didn’t appear fully formed. They evolved slowly, iteratively, and sometimes unexpectedly much like the early stages of human reasoning. Today’s Agentic AI systems, capable of coordinating multiple specialized agents to pursue complex goals collaboratively, are the result of decades of refinement.
If Episode 1 traced the shift from prediction to generation and onward to automation and autonomy, this episode dives into the building blocks of autonomous behavior, the different types of AI agents that form the foundation of today’s intelligent systems.
Each agent type represents a distinct way of “thinking” about the world, from reacting instantly to planning strategically.
1. Simple reflex agents, intelligence as instant reaction
The most primitive form of artificial intelligence. Reflex agents operate like a thermostat: see something → react immediately. They have no memory, no context, and no anticipation. Fast and predictable, but limited when situations become ambiguous or complex.
Strength: Extremely fast and predictable. Limitation: Easily confused by complexity.
2. Model-based agents, when perception meets memory
Model-based agents maintain an internal representation of the world. They remember recent events, infer hidden state, and update their internal model as new data arrives. This ability to hold a model of the environment enables better handling of partially observable situations.
Strength: Can reason about partial observability. Limitation: Still fairly reactive with limited long-term planning.
3. Goal-based agents, intelligence gains direction
Goal-based agents act with purpose. Instead of merely reacting, they evaluate actions by whether those actions bring them closer to a defined objective. These agents can plan, sequence tasks, and weigh alternative paths before acting.
Strength: Capable of planning and sequencing. Limitation: Goals are externally defined and typically not self-generated.
4. Utility-based agents, choosing the best action
Where goal-based agents ask “will this achieve the goal?”, utility-based agents ask “how well will this achieve the goal?” Utility introduces trade-offs, preferences, and optimization into decision-making allowing agents to balance multiple criteria and pick the best outcome.
Strength: Nuanced decision-making and optimization. Limitation: Designing robust utility functions can be difficult.
5. Learning agents, systems that improve themselves
Learning agents adapt from experience. Instead of relying solely on rules or fixed models, they update their strategies based on feedback and outcomes. This learning capability is central to modern agentic architectures that refine behavior continuously.
Strength: Self-improving and versatile. Limitation: Can be hard to control and may amplify biases if not carefully governed.
6. Multi-agent systems, when intelligence becomes collective
The most powerful and complex form: multiple specialized agents collaborate, communicate, and coordinate. Modern Agentic AI often composes orchestrators, planners, memory systems, and role-specific agents that together solve tasks no single agent could handle alone.
Strength: Scales to complex, multi-step problems. Limitation: Coordination, safety, and emergent behaviors become central challenges.
A clear trajectory
When we zoom out, the evolutionary path becomes clear:
- Simple reflex → react instantly
- Model-based → maintain a state
- Goal-based → pursue objectives
- Utility-based → optimize trade-offs
- Learning agents → improve from experience
- Multi-agent systems → collaborate and orchestrate
What started as simple reaction loops has grown into coordinated, memory-driven, goal-oriented networks capable of planning, learning, and cooperating in ways that echo human organizations. This evolution explains why Agentic AI is more than automation: it’s the emergence of structured, collaborative, adaptive intelligence.
