UOM for the physical dimensions of the Items

I would like to know what is the unit of measure of the physical dimensions of the item. We only have the UOM of the item but we can’t find out the unit of the physical dimensions such as height, width, depth. How would the system differentiate if the height defined is in cm or inches 

In addition, how will the items or products physical dimension affect the containerization process?

In Warehouse Management if we set the Container Type Volumes unit to CBM, can we set the physical dimension of the item to cm or inches?