Rice flour is ground from long- or medium-grain rice, the rice that we usually eat. It has some thickening properties and it is a good gluten free substitute for wheat flour in baking. (100g / 359 kcal)
Sweet rice flour is ground from a high-starch, short-grain rice, or "sticky rice (mochiko),” to use as an effective thickener for sauces or binder for mochi. Sweet rice flour is also used for confections, noodles and sauces in many Asian countries. (100g / 360 kcal)
Rice is transparent whereas glutinous, or sweet rice is opaque. Rice starch is mainly composed of amylose and amylopectin. Sweet rice is composed of nearly pure amylopectin. This characteristic makes it very viscous and useful as a superior thickening agent by inhibiting liquid separation.