A stimulus is any change or event that triggers a response in living beings. It can be something external, like light or sound, or internal, like hunger or pain. When an organism detects a stimulus, it reacts in some way. For example, when you touch something hot, the heat is a stimulus, and your body quickly responds by pulling your hand away. Stimuli help organisms react to their environment and stay safe.

This question related to Chapter 9 Science Curiosity Class 6th NCERT.
From the Chapter 10. Living Creatures: Exploring their Characteristics.
Give answer according to your understanding.