Answer: hello dear, your question seems incomplete, but, chill out not to worry let me give you one or two things you need to know in order to be able to solve this kind of question in the nearest future, check this out!.
Explanation:
In order to kill parasites and to make the water the be safe from microoganisms, boiling is a great procedure for making sure this happens, that is to say is the act of purification of water. However, when you over-boil water it also depletes the amount of oxygen present in the water.
When you boil water for the purpose of killing germs/ parasites, the PURIFIED PART IS THE WATER VAPOUR, the LIQUID WATER STILL HAS THE DEAD PARASITES IN THEM. That is the reason why the process called DISTILLATION is more efficient in purifying water is more efficient than ordinary boiling of water.
The liquid water remaining in the container after the boiling would have also been purified though, but it will still contain dead contaminants, so, filtering can be done or one can drink the water like that.