Penumbra

Real World Example

Imagine you're at a crowded party, trying to hear your friend's voice amidst the noise. This situation is similar to the penumbra because just as your friend's voice is partially drowned out by surrounding chatter but still discernible, the penumbra is a lighter shadow that exists around the darkest part, where light partially reaches. The connection here is that just like the friend's voice being partially clear despite surrounding noise, the penumbra is a region where light is partially blocked, creating a lighter shadow amidst the surrounding darkness.