Gin is distilled from grain and receives its unique flavor and aroma from juniper berries and other botanicals. Every gin producer has his own special recipe, which is under strict quality control. The flavor of gin will vary with the distiller. Gin was first produced in Holland by Dr. Sylvius, a Dutch physician, during the 17th century. He named it Genievre, the French word for the juniper berry. It was the English who shortened the name to gin. Brought from Holland into England by English soldiers, who called it “Dutch Courage”, gin soon became the national drink of England and has so remained.
Gin can be made two ways, by either being distilled or compounded. All leading popular brands sold in the United States are distilled. Compounded simply means a mixture of neutral spirits with juniper berries. Distilled gin is distilled completely.
Dry? Extra Dry?
Virtually all gins in the United States use the word “dry.” You will see it on brand labels that may read, “Dry Gin,” “Extra Dry Gin,” “London Dry Gin,” or “English Dry Gin,” but they all mean the same thing‑‑lacking in sweetness. Originally, “London Dry” meant gin produced in London, but the name “London” is considered to be generic, and therefore it is often used to describe gins produced in the United States.
Information via American Bartender's School