[joveian]

Some glass is also plastic. But I think outside technical discussions and deceptive marketing glass is usually used to refer to borosilicate or soda-lime since those are what most widespread glass products were for a while. Recently there are more varieties of glass that are marketed as glass to take advantage of the good reputation (in some ways) of borosilicate and soda-lime. But this is like using the term fruit in a technical way, it is just not what most people mean by the term glass.