Unit

A unit is a person or animal controlled by the player or an NPC which moves through the world.

Abstraction
For animal units, a single unit represents a small group of animals: a pride of lions, or a pack of wolves.

For non-animal (human) units, a single unit represents a small, cohesive group of people, like an extended family or clan. These people move through the world together, and the location of the unit on the map represents the primarily location where their industry is focused.

A unit's individual members are not represented directly in gameplay, but it can generally be assumed that its nonworking members like children and their caregivers are actually located at the unit's dwelling (e.g. whatever location is currently supplying its rest), while working members are located at the tile where the unit is depicted. At any given time several individuals from the group will also be out along its supply lines, fetching food, hauling harvested goods back to town, etc.

If a unit is destroyed, it means that enough of the clan's members have been killed or driven off that it ceases to exist as a cohesive entity, and any surviving members can be presumed to have joined other clans or departed the civilization altogether.