A charge-station which is installed on a wall. Wallboxes are usually smaller and less pricey than a charging-pillar with it’s associated installations (earth-works, foundation, alignment).
Wallboxes are most often installed for personal used, for example in private garages.
In the context of fleet-charging wallboxes are often installed next to each other on a wall or on cross-beams. Cables are usually routed above ground in these cases.
Wallboxes are rarely used for public charging.