An intelligent agent (IA) in the context of artificial intelligence is an autonomous entity that perceives its environment through sensors and interacts with that environment using actuators to achieve specific goals. These agents can range from simple systems like thermostats to complex ones such as autonomous vehicles or even more abstract entities like firms or states.
A self-driving car is an example of an intelligent agent, as it perceives its environment through cameras and sensors, and interacts with that environment by controlling the steering wheel, accelerator, and brakes to reach a specific destination.