Fence jumping is the act of surmounting a height-based physical barrier like a fence, gate, or wall in order to gain access to a restricted area. Depending on the barrier's height, you may find it easier to go over it than attempt to go around it or through it. For example, some fences are only three to four feet high and are designed to prevent someone from casually walking up to an area they shouldn't be accessing. The fence may extend all along the perimeter, and is likely made of metal that is not easily bent or broken without the proper tools. Therefore, going over the fence could be the most viable option. However, someone attempting to climb or literally jump over the fence may attract suspicion if seen.
More restrictive premises will likely install taller fences, usually above eight feet, that cannot be jumped and must be climbed. Not only will these fences attract suspicion, but they are also designed to be difficult to climb over without considerable effort. A ladder may aid in your efforts to scale a tall fence, though again, this could draw suspicion.
More extreme anti-fence-jumping measures can come in the form of barbed wire or razor wire at the top of the fence. Even if you manage to scale the fence, you will have a difficult time actually going over it without injuring yourself. This acts as a powerful deterrent. However, sections of barbed wire and razor wire can be cut with the right tools, enabling passage over the fence without harm.