system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why is it when some wounds heal, they leave a shiny scar, whereas others leave dark patches of skin?

Does it have to do with the size, type or depth of the injury? How to reduce the size or colour of the scar?
gpt
It deals with how that particular injury heals. Your skin is multilayered. The very top layers are actually dead. Underneath are the living tissues, softer, "normal skin" layers closer to the surface and "basal" layers below. These basal layers are slightly different from the ones closer to the surface and when you are injured, they play a role in 'filling the gap'. In small, superficial wounds, everything heals up to 'normal'. But not all the time. Sometimes the wound closes with those basal layers comprising most of the 'new' skin.