Bottled water is not necessarily soft water. Much of the bottled water sold in stores is plain tap water, some is from springs containing various minerals in solution, and some is distilled water.
It depends on where you live, there are websites you can use to find out if you live in an area with hard or soft water.
Hard water has more minerals in it.
No. They are not the same. Distilled water is only water. Boiled water will likely contain minerals.
You have to melt it