Which of the following is classified as digital input?

Digital input refers to signals that represent information in binary form, typically using discrete values, such as high and low (1 and 0), which correspond to different states. In this context, keyboard input is classified as digital input because when a key is pressed, it generates a specific binary code that the computer understands as an instruction. Each key corresponds to a unique binary representation, allowing the system to process user input effectively.

On the other hand, temperature sensor readings and voltage levels in a circuit can yield a range of values and are typically considered analog inputs, as they do not conform to the binary high/low classification. Light intensity managed through PWM (Pulse Width Modulation) also involves varying levels rather than a strict binary signal, making it distinct from digital input. Thus, keyboard input is the only option that explicitly fits the definition of digital input in this scenario.