There is a difference between "pyrex" and "PYREX", but the difference is which company owns it rather than necessarily what it's made of.

However there is truth to it. European PYREX is now exclusively made from borosilicate glass (the original material). There is older PYREX brand stuff made of other materials, but new stuff is all borosilicate. All pyrex glass stuff is now soda-lime glass instead of borosilicate.

Basically, if you're buying new, the brand is a fine indicator. But if you're buying anything second hand, the logos won't help you as all three variants of the branding (Pyrex, PYREX and Pyrex) have made products with both materials at various times.