Boiling water kills any microbial life.
Boiled water is not necessarily safe. Increasing the temperature will kill microbes and break down organic molecules. It will also break down some inorganic compounds, but won’t remove things like Arsenic or Salt. Water with Arsenic in it still dangerous even after boiling.
Edit: the question was merged. To answer the merged question, filtering out harmful chemicals and boiling water to destroy most harmful microbes is guaranteed to make water safe.
In most places in most developed nations, water is considered safe to drink from the tap without boiling it. In Australia which has safe water, I drink filtered tap water at home without boiling it, unless I am making coffee. I drink tap water unfiltered often when I am at restaurants
Source:
www.quora.com
