Right from my school days I've been involved in all layers of developing apps - assembler, C, Java, HTML, PHP, Django, databases, HTML/CSS/JS. Many years before

Right from my school days I've been involved in all layers of developing apps - assembler, C, Java, HTML, PHP, Django, databases, HTML/CSS/JS. Many years before this "full stack developer" popped up, I never thought being involved in all the layers of developing apps needs a name of its own. For me it was just being able to do both frontend and backend. So when "full stack developer" roles first begin to pop up in the industry, it left me very confused. Why a whole new name for it? How exactly is it defined? Am I a full stack developer or am I not?