The loop behind every robot
A robot vacuum senses a wall (sense), decides to turn (think), then spins its wheels (act) — over and over. Sense-think-act is the simple loop running behind every robot, from a toy to a Mars rover.
How a machine decides
A robot repeats a simple loop: it senses the world, thinks about what it found, and acts. Sensors are its senses — cameras, distance detectors, touch switches. Actuators are its muscles — motors and wheels. The 'thinking' is a program deciding what to do next.
Round and round
The loop never stops while the robot is on. Every fraction of a second it senses again, so it can react to a wall, a line, or a hand in its way.