The Sun

As we already know, fire is one of the main elements.  It exists everywhere around us and is only present when there is a presence of oxygen.  Now when we were discussing space, a serious question popped into my mind…  How does the sun stay on fire when there is no oxygen in space?  Originally my mind was absolutely blown and I thought that everything I have ever learned about fire was false.  However, I turned to google to provide an answer.  It turns out that the sun doesn’t use oxygen to burn since it does not use any chemical combustions.  There is constant nuclear fusion going on within the sun, and bonds can be formed using substitutes.  This made me think though,  could the sun and stars be considered elements in itself?  Although they are a part of our solar system,  could it be considered an artificial fire since there is no oxygen?  It is essential a nuclear burning instead of fire burning.  This is just some interesting food for thought!!