That’s ok! I didn’t know anything about NPOs until I started working for one. Even now, I’m still trying to figure everything out. 

NPOs mainly rely on donations from the individuals or, sometimes, businesses. Those donations are used to supplement the activities that are a part of a particular NPOs purpose. Most NPOs will keep a percentage of each donation in order to pay their full and part time staff. That basically means you won’t be making a lot of money working for them and, yes, they mainly have to rely on voluteers because they just don’t have the money to pay people to do everything that needs to be done to successfully carry out it’s structures and purposes. 

Keep in mind that I’ve only worked ONE NPO so, again, no expert here. That’s just how I’ve mainly seen it work.