It is important to realize how important fences truly are before dicusssing anything else. Fences have been used since very early on in history, starting with the Neolithic Revolution, where they were used to protect livestock and crops from predators and house cattle. This was the reason modern societies could even exist due to the transition between hunter-gatherer societies to agricultural and trading civilizations.
There is a debate regarding what requirements something has to have to truly be considered a fence. One of WVU Fence Club's missions is to create guidelines that leverage academic research, industry standards, and practical real world use that layout what truly defines a fence.
The following are Work in Progress guidelines that describe the characteristics of a fence:
Must have defined posts
Cannot have continuous contact with the ground along its full length (can be attached to top of a wall)
Must not contact a ceiling on its top
Must have supporting structure bonded in the middle between posts
Air must be able to pass through