X4: Foundations – Container Storage / Build Storage
When you start building a station, the first thing added or created is a so-called “Build storage”. This is essentially a fragile tower of containers near your future station where transporters can deploy the resources needed for building. It grows over time as more resources are in stock for building (management happens over the build UI).
In contrast to this, the operational station has internal storage through its ware storage modules. This means an operating station can have two separate sets of storage that also give separate trade offers. You can tell the difference on the map through the little “build” icon.
If your station happens to have the same resources that your build storage needs, the transfer between the two can happen automatically (through XS ships). Normally, ships with WARE EXCHANGE orders are needed for this.