Staples are fasteners formed from a crown that bridges two legs; when driven into a material, the legs pierce it and hold the pieces together. Their dimensions and point shape suit different fastening jobs. Lightweight staples are associated with lighter-duty fastening, while carton staples are designed for securing packaging. Narrow-crown staples have a slimmer bridge across the legs, and point styles such as presser points describe how the legs are shaped to enter material. Together, these examples show how a simple U-shaped fastener can vary to suit different materials and levels of holding strength.