Polywire
Polywire is a type of plastic-coated wire that is used for electric fencing.
This type of wire is usually used for temporary electric fences, electric fences for livestock and other types of electric fences for animals. It's not really ideally suited to use for permanent electric fences or high security fences.
Because of the plastic coating on the outside of polywire for electric fencing, it's very visible, which is a safety feature for anyone who might be working or walking in a field that is secured with this type of electric animal fencing.
Polywire is also a low-cost electric fence wire option, and if it is installed and taken down carefully, it can be reused for portable electric fences as needed.