What encompasses hardware or software systems designed to carry out tasks automatically on behalf of humans?

The correct choice identifies robots as hardware or software systems designed to carry out tasks automatically on behalf of humans. Robots are specifically engineered to perform a variety of tasks, often involving physical movement or manipulation of objects. This can range from simple repetitive actions to complex operations requiring a blend of both software and hardware components. Robots can be autonomous or semi-autonomous, relying on programming and algorithms to function effectively.

While automation tools, artificial intelligence systems, and smart devices also play a role in automating tasks, they don't specifically define the category of robots. Automation tools tend to refer more broadly to software applications that help automate processes, whereas artificial intelligence systems focus on mimicking human cognitive functions rather than physical tasks. Smart devices, on the other hand, are typically consumer electronics that connect to the internet and perform functions remotely, but they do not encompass the full range of capabilities associated with robots. Therefore, robots represent the most precise answer in identifying systems designed specifically to automate tasks for humans.