True meaning of Volunteerism

I always wonder what is the true meaning of “Volunteer” and how or when can we use the word “Volunteer”? If I search in dictionary.com, Volunteer means that “a person who voluntarily offers himself or herself for a service or undertaking”. It can be also mean that “a person who performs a service willingly and without pay”. 

So, what are you going to do if you are actually being told to do something and you are not willing to do it, but because of some reason, you have to do it, else you will have to face the consequences. So, is it still consider as volunteer? What is volunteer?

I always wish that I able to voice out this question, however, due to some reason, I try not to because it will definitely become an issue and “some people” will use it to attack me. That is why I choose to keep quiet and just be calm. Nothing much I can do because I am not an important person, just need to make sure I am myself. What goes around, comes around. So..stay calm and be sincere and positive.