Edges, also known as crimps or crimpers, are smaller holds that often meet the wall flat (or at 90 degrees) but can also have a bit of bite to them (meaning they are positive holds, kind of like mini-jugs) or can be very difficult to hold onto if they meet the wall at a negative angle (greater than 90 degrees). Regardless, edges are rarely bigger than one finger pad in width and require more advanced strength to hold onto. The grip used on an edge is called crimping and involves holding on with just your finger pads and creating friction by bending at the second knuckle. Edges are an integral part of any climbing wall as they can be used to create more difficult climbs as well as to help strengthen your fingers as you progress. Many of the climbing holds you will find outdoors on real rock are some variation of an edge which means that having them on your home wall can help to prepare you for climbing outside!