Ais where one network ends and another begins.

A demarc is where one network ends and another begins. Demarc stands for demarcation point. It is the physical point at which the public network of a telecommunications company ends and the private network of a customer begins.

However, the distinction between where one category of network begins and another ends is sometimes blurry.

those characteristics are cellular organization, reproduction, metabolism, homeostasis, heredity, response to stimuli, growth and development, and adaptation through evolution. some things, such as a virus, demonstrate only a few of these characteristics and are, therefore, not alive