Fences are the structures that enclose an area and are typically placed outdoors to serve as a physical barrier. Fences are usually constructed from posts that are then connected through boards, wires, rails, or netting. Fences are different from walls as they don’t have a foundation that runs along their entire length. Fences are made from different materials to fit their function and environment. Fences are produced in various heights and may have decorative elements. Fences are also a way to mark property or protect it. The types of Fences include agricultural fencing, privacy fencing, perimeter fencing, decorative fencing, school fencing, or pet fence.

Fences have a long history, dating back to ancient civilizations. In 3200 BCE, Mesopotamia used stone and wood to demarcate boundaries, protect crops, and confine livestock. The Greeks and Romans built stone walls for defense, land demarcation, and privacy. Medieval Europe saw the rise of moats and castles, with fences surrounding fields and gardens. The Industrial Revolution in the 19th century popularized mass-produced, cast iron and barbed wire fences. In modern times, fences serve various functions including security, privacy, and aesthetics.

The future of fences and boundary walls embraces both aesthetics and function. Modern designs lean towards green walls covered in plants or modular fences that can be reshaped as needed. For security, smart fences come equipped with sensors and cameras. In urban settings, soundproofing features are gaining popularity to combat noise pollution. Examples like the "living wall" in London show a blend of nature and architecture. As cities grow and privacy needs evolve, fences and walls adapt, becoming more than just barriers.