A digital footprint is all of the information on-line about a person posted by that person or others, . intentionally or unintentionally unintentionally or accidentally intentionally recklessly

A911 dispatcher is the sole sender of messages to all police officers. while on patrol, officers communicate with the dispatcher who, in turn, relays messages to other officers. the officers do not communicate directly with one another. this illustrates a network.

Which of these is most responsible for differences between the twentieth century to the twenty-first century?

What are "open-loop" and "closed-loop" systems