An intelligent agent is an AI hardware and/or software system with some degree of autonomy and the capacity to make decisions and take actions.
Intelligent agents are more advanced than conventional agents, or bots, whose actions are wholly programmed. An agent program might, for example, use human-defined parameters to search a knowledge base or the Internet and organize that information for presentation to the user.
Intelligent agents, at their most complex, include physical systems, such as AI-equipped android (humanoid) robots. Although it has not yet been demonstrated, some believe that a future system could not only look like a human but could also replicate human cognitive powers in artificial general intelligence (AGI) or even overwhelmingy surpass it in artificial superintelligence (ASI).
At the lower end of the scale lie more task-specific software programs, such as expert systems, that work similarly to conventional agent programs but nevertheless some degree of autonomy, and physical agents that take in sensor data and act on it.