What storage through a mover involves
Storage from a mover is different from renting a unit. The crew inventories and wraps your goods at pickup, loads them into sealed wooden vaults or containers, and stores those vaults in the carrier's warehouse or an agent's. When you set a delivery date, the vaults are opened, the goods go onto a truck, and everything is checked off against the same inventory at your door.
On an interstate move this is usually called storage-in-transit: the shipment pauses with the mover between origin and destination. After a set period, most tariffs convert it to permanent storage, which changes the paperwork and often the liability. Ask each carrier when that conversion happens and what changes with it.
Self-storage still makes sense in some situations, mainly when you need to get at your things often. A mover's warehouse is built for goods that sit untouched until delivery.
