What is a living will or health care directive, and why is it important to have one?

A living will is a document in which you say what your wishes are should you be at end of life. Its also known as an advanced directive; it's also known as a healthcare directive. It allows you to write down what your wishes are so that they will be honored when you are unable to speak for yourself.

If you are at end of life in a terminal condition or permanent vegetative condition what heroic measures would you want if any? It's extremely important to write down what your wishes are so that they be known and so that they be honored.