Cake flour is a fine flour that is finely milled from soft winter heat, it has one of the lowest protein (gluten) counts, lower than all-purpose flour and many other flours. It is finer, lighter, and softer than many other flours. It is also bleached so that the color is even paler and the grain is not so dense. If you compare cake flour to all-purpose flour you will notice in the visuals that it is very different.
The bleaching of the flour in cake flour means that the flour repels liquids, binds fats and stabilizes gas bubbles produced in the rising process. These are the features that give a rising cake more fluffiness, a more tender texture and that cakey feel that you seek, especially in cakes that have a high sugar count in their recipe.