In Iyengar Yoga we use props such as sticky mats, blocks, straps, blankets, bolsters, chairs, walls, ropes, and sand bags to name a few.  When students begin taking yoga classes, they will likely use a sticky mat, blocks, straps, and blankets.  These items are used to promote stability, ease, and achieve alignment in poses. To use the props properly skill is needed. Intelligence of props use  comes from  repeated practice during class and at home. The instructor will give steps on how to place the props while doing a pose. Props are our friends and the more we learn to handle them correctly the better our yoga practice will be.