A WWE ring's corner structure, displaying the ring ropes' connection to the ring post through the cushioned turnbuckles. The traditional wrestling ring's configuration and construction are quite similar to that of a boxing ring. Wrestling circles, like boxing rings, have the poetic term of the "squared circle." That is, there are four defined corners to the ring. The key difference between a wrestling ring and a boxing ring is the presence of the guard rail. In a boxing ring, there is only one type of fence used, which is called a "ring fence." This is a single horizontal bar that extends around the perimeter of the ring. It serves as both a safety measure and as a means of containment for the boxers during a fight. There is no guard rail in a boxing ring because the ring is considered an extension of the fighting area and its use is not necessary for boxing safety. In contrast, a wrestling ring has a guard rail on three sides but not on the fourth. This is because it is not necessary to protect the wrestlers from outside interference in wrestling; therefore, there is no need for a fourth side fence. Furthermore, wrestling rings are built with the goal of creating a battle zone where wrestlers can test their strength by trying to force each other out of the ring. When a new wrestling ring is constructed, it is designed with a flat floor so that wrestlers can give it a try before buying it.