Size can be subjective; what’s big for one scale may be small on another.

The idea of 'big' depends on what you compare it to. A human is huge compared to a virus, but tiny compared to a mountain. A mountain is massive to us but just a small bump on Earth’s surface. This shows that 'big' isn’t a fixed number but a relative idea. Understanding this helps us think clearly about size and scale in everyday life and science.