what is a fence?

Fences Video Demo

Fences is a program to organize your desktop icons better. A fence is some sort of container you can throw icons in. You can move it around and resize it, and the icons will move, too.

https://www.stardock.com/products/fences/

It's also a real world item that look like this:

(wikipedia)

I would assume the reason the software is called fences is because it restricts icons within an area on the desktop the way a real fence restrict cows on a field.

It's something we need to put around this place!