It gives a concentrated brandy flavour, which would otherwise require a much higher quantity of brandy when that amount of liquid wouldn’t be appropriate in a recipe.
Most brandy extracts actually do contain, however, a very small amount of alcohol, making them out of bounds for Muslims. The Clubhouse brand contains the following ingredients: Propylene Glycol, Water, Alcohol, Artificial Flavour, Colour.
Another flavouring extract such as vanilla or rum, or per qty of brandy extract called for, an equal quantity of apple or white grape juice, or just water.
5 tablespoons of brandy = 1 tablespoon brandy extract
Also called “Imitation Brandy Extract”.