The ratio "3:4" represents a relationship between two quantities, indicating that for every 3 units of one quantity, there are 4 units of another. This ratio can be applied in various contexts, such as in mathematics, art, and design. It is often used to describe dimensions, such as the aspect ratio of a rectangle. In practical terms, if you have a rectangle with a width of 3 units, its height would be 4 units to maintain the 3:4 ratio. This ratio is commonly found in photography and screen resolutions, where it helps create balanced and visually appealing compositions.