Pyrex is the brand name for a well-loved heat resistant glassware product, introduced by the Corning company 100 years ago. Today Pyrex is typically utilized in the lab with test tubes, dishes, and beakers. Pyrex is used in the kitchen for baking, stovetop cooking, and utensils, including mixing bowls and storage containers. Pure Glass is not as sturdy as Pyrex because Pyrex is four to six times tougher with a granular breaking pattern.
Regular Glass is not made for abrupt changes in temperature, and Pyrex can tolerate temperature changes, so says their tag line, "from the freezer to the oven, to the table." A glass of all types, including Pyrex, made for baking, can not be used on direct flame or heating sources. There is Pyrex that may be used on top of the stove for cooking and coffee making. The main difference between Pyrex and Glass is that Pyrex is tempered Glass and used for cookware. Glass is used for architecture and furniture.