What is the position right the Position Drive to Diskstation perpendicular or horizontal

Who stay this in the Quick Install Guide.

What is the normaly working position from Drive perpendicular or horizontal.

Is it the same mounting position which the disk has?

Sory for my question. Im a nivice to install a Diskstation.

Thanks have a good Day.

it doesnt matter the position… if the drive stays fit will work fine on any position