Fence

A fence is a structure that encloses an area, typically outdoors, and is usually constructed from posts that are connected by boards, wire, rails or netting. A fence differs from a wall in not having a solid foundation along its whole length.

Alternatives to fencing include a ditch (sometimes filled with water, forming a moat).

Types
By function

Agricultural fencing, to keep livestock in and/or predators out
Blast fence, a safety device that redirects the high energy exhaust from a jet engine
Sound barrier or acoustic fencing, to reduce noise pollution
Crowd control barrier
Privacy fencing, to provide privacy and security
Temporary fencing, to provide safety, security, and to direct movement; wherever temporary access control is required, especially on building and construction sites
Perimeter fencing, to prevent trespassing or theft and/or to keep children and pets from wandering away.
Decorative fencing, to enhance the appearance of a property, garden or other landscaping
Boundary fencing, to demarcate a piece of real property
Newt fencing, amphibian fencing, drift fencing or turtle fence, a low fence of plastic sheeting or similar materials to restrict movement of amphibians or reptiles.
Pest-exclusion fence
Pet fence, an underground fence for pet containment
Pool fence
Snow fence

A balustrade or railing is a fence to prevent people from falling over an edge, most commonly found on a stairway, landing, or balcony. Railing systems and balustrades are also used along roofs, bridges, cliffs, pits, and bodies of water.

By construction

Brushwood fencing, a fence made using wires on either side of brushwood, to compact the brushwood material together.
Chain-link fencing, wire fencing made of wires woven together
Close boarded fencing, strong and robust fence constructed from mortised posts, arris rails and vertical feather edge boards
Expanding fence or trellis, a folding structure made from wood or metal on the scissor-like pantograph principle, sometimes only as a temporary barrier
Ha-ha (or sunken fence)
Hedge, including:
- Cactus fence
- Hedgerows of intertwined, living shrubs (constructed by hedge laying)
- Live fencing is the use of live woody species for fences
- Turf mounds in semiarid grasslands such as the western United States or Russian steppes

Hurdle fencing, made from moveable sections
Pale fence, composed of pales - vertical posts embedded in the ground, with their exposed end typically tapered to shed water and prevent rot from moisture entering end-grain wood - joined by horizontal rails, characteristically in two or three courses. Also known as "post and rail" fencing.
Palisade, or stakewall, made of vertical pales placed side by side with one end embedded in the ground and the other typically sharpened, to provide protection; characteristically two courses of waler are added on the interior side to reinforce the wall.
Picket fences, generally a waist-high, painted, partially decorative fence
Roundpole fences, similar to post-and-rail fencing but more closely spaced rails, typical of Scandinavia and other areas rich in raw timber.
Slate fence, a type of palisade made of vertical slabs of slate wired together. Commonly used in parts of Wales.
Split-rail fence, made of timber, often laid in a zig-zag pattern, particularly in newly settled parts of the United States and Canada
Vaccary fence (named from Latin vaca - cow), for restraining cattle, made of thin slabs of stone placed upright, found in various places in the north of the UK where suitable stone is had.
Vinyl fencing
Solid fences, including:
- Dry-stone wall or rock fence, often agricultural
- Stockade fence, a solid fence composed of contiguous or very closely spaced round or half-round posts, or stakes, typically pointed at the top. A scaled down version of a palisade wall made of logs, most commonly used for privacy.* Wattle fencing, of split branches woven between stakes.

Wire fences
- Smooth wire fence
- Barbed wire fence
- Electric fence
- Woven wire fencing, many designs, from fine chicken wire to heavy mesh "sheep fence" or "ring fence"
- Welded wire mesh fence