Deterministic processes produce the same output given identical inputs every time.

Traditional automation is deterministic. Run the same workflow twice and get identical results.

Probabilistic processes involve uncertainty and variance. AI agents are inherently probabilistic because LLMs generate different responses to the same prompt.

This means agents can handle nuanced situations but may produce varying results.

Most agent implementations blend both approaches - deterministic workflows for critical paths and probabilistic reasoning for complex decisions. Understanding this distinction helps you design appropriate oversight and error handling.