Final answer:
Humans consume food and convert its energy into useful work, while robots require electricity as their power source and convert it into mechanical energy to perform tasks.
Step-by-step explanation:
Humans and robots have different inputs and outputs in terms of matter and energy. Humans consume food as an input and convert the chemical energy in the food into useful work. This work can be physical activities or mental processes. Robots, on the other hand, require a power source, such as electricity, to function. They convert electrical energy into mechanical energy to perform tasks. While both humans and robots utilize energy to do work, the sources and mechanisms of energy conversion differ between the two.