Barbed wire is a type of fencing material made of strong wire with sharp edges or points. It is designed to deter animals and people from crossing boundaries. The wire is typically twisted together to form a series of barbs, which can be spaced at regular intervals. Originally invented in the late 19th century, barbed wire became popular for use in agriculture and military applications. It is often used to secure farms, ranches, and military installations, providing an effective barrier while being relatively inexpensive and easy to install.