ï· An introduction to AT&T and its global security organization, ï· A summary of customersâ security responsibilities, In general, the use of âsecurityâ throughout this document refers to âinformation and network. securityâ.
arch definition In architecture, a curved or pointed opening that spans a doorway, window, or other space. Note: The form of arch used in building often serves to distinguish styles of architecture from one another.
The central feature of an arch is the keystone, or the wedge-shaped stone at the very top of the arch. It is the last stone placed during construction, and it locks all the other stones of the arch into position. The keystone bears almost no weight, but is the center of redirecting the weight of the structure down and outwards. The Romans used arches with circular tops, called rounded arches, which were made of stone.