What is a "highball glass"?

A highball glass is a tall glass commonly used for serving mixed drinks, particularly those made with a high ratio of non-alcoholic mixer to alcohol. It typically has a capacity of around 8 to 12 ounces and is characterized by its narrow width and tall height, allowing for the addition of ice and mixer while still leaving room for the drink itself. Highball glasses are commonly used for cocktails such as the classic Gin and Tonic, Whiskey Highball, and Vodka Soda, among others.