A bounded agent is the opposite of an unbounded agent and refers to agents that operate under realistic conditions and resource constraints. Bounded agents only have realistic amounts of computing power, RAM, and disk space (no more than fits into one Hubble volume). They act in real time, meaning that time in the external world goes on passing as they deliberate. They don't have perfect knowledge of the environment. Their sensors are noisy and require probabilistic inference. They can only act on the environment through motor outputs. Their environments are bigger than they are, and can't be fully simulated in realistic amounts of time.