Update ONE

An ordinary Power of Attorney is only valid as long as the Principal is capable of managing his or her own affairs.

It becomes invalid when the Principal loses capacity (loses the ability to make important decisions). 

A "durable" Power of Attorney, if created before the Principal loses capacity, will remain valid even after capacity is lost.

If you want your Attorney-in-fact to make decisions for you after you have lost the ability to make decisions for yourself, then you should choose "durable".