Ginger beer is actually most similar to golden-style ginger ale. It's made with a mixture of ginger, sugar, and lemon juice fermented with a ginger beer culture. The result is a slightly cloudy, strong, and spicy ginger beverage. Traditionally, ginger beer also contained alcohol. Though modern versions are usually non-alcoholic (contain less than 0.5% alcohol). In comparison, classic ginger ale contains no alcohol and isn't fermented. It has a far lighter/mellower appearance, odor, and taste (also sweeter). It's essentially a ginger-flavored soft drink.