The shower door position is completely up to the owner, but most doors are situated opposite the shower head and drain. Some shower doors may be placed directly in front of the showerhead and drain or are placed to its left or right for sliding doors. Be aware of where you install a shower door so you can safely and comfortably exit and enter the shower.
Smaller bathrooms with a shower in the corner or an oddly-shaped shower may be better off with sliding doors. If a hinged shower door is installed so it swings inward and outward, it is essential that the door not hit any nearby walls, sinks, toilet, or other fixtures.