The act of glassblowing itself dates back to around 50 B.C. in the Roman Empire. Glassblowing was traditionally done in monasteries and was solely for functional objects. It wasn't until the 1960's that glass became popularized as an art medium. Glass is made from fusing together sand, soda, and limestone with heat. Limestone is a resource that is abundant in this region of Europe, making glass a good asset for them.
Heated glass takes on a liquid, molten form.
The glassblower, known as a Gaffer, keeps the glass molten by storing it in a furnace. There are many different individualized techniques to blowing glass. One that is popularized in the Black Forest and dates back to the original techniques is that the glassblower takes a long hollow metal staff and dips it into the furnace. He dips it until a glob of molten glass fuses to the end of it. Then the glass is dipped into bins of shaved color glass pieces until the desired array of colors is achieved.