Glutinous rice flour is made from glutinous rice (also called sticky rice or sweet rice) and is commonly used in Chinese desserts and snacks.
Glutinous rice flour can also be used to make the popular Japanese dessert, mochi! See a video from Nami from Just One Cookbook for instructions:
Glutinous Rice Flour, Water
Stick it in the cupboard, store it in an airtight container after opening.