Glass blowing is a glass forming technique that involves inflating molten glass into a bubble with the aid of a blowpipe or blow tube.
The technique of glass blowing was invented by the Phoenicians in approx 50BC. The earliest evidence of glass blowing comes from a collection of waste from a glass workshop dumped in a ritual bath in the old city of Jerusalem from 37 to 4 BC. Glass blowing was encouraged under Roman rule from the first century BC and this helped to see the art spread across the Roman Empire. Rome, the heart of the empire soon became a major glass blowing centre. A great variety of glass blown objects were produced, from perfume bottles, to table wear, to windows.
The glass blowing tradition was carried on in Europe from the Medieval period, through the Middle Ages to the Renaissance. The applicability of glass blowing became so widespread that glass was being blown in many parts of the world including China, Japan and the Islamic Lands.
The "Studio Glass Movement" began in 1962 when Harvey Littleton and Dominick Labino held two workshops at the Toledo Museum of Art during which they started experimenting with melting glass in a small furnace and creating blown glass art. Littleton promoted the use of small furnaces in individual artists studios. This approach to glass blowing blossomed into a worldwide movement.
Here are some great examples I have found of glass blown pieces on Etsy: