Which term means energy or information entering a system?

• A. Output
• B. Process
• C. Input
• D. Testing

Answer: (C)

Think about what a system takes from the outside world to work. The thing entering the system—whether energy, materials, or data—is called input. The system then uses that input through its internal actions (the process) to produce something new, which is the output. For example, a computer takes input from a keyboard or sensors, processes it, and displays output on the screen. A factory takes in raw materials as input, processes them, and delivers finished goods as output. So the term for energy or information entering a system is input. Output is what leaves, the process is the change happening inside, and testing is about checking results.