Communications system in the context of "Information technology"

A public utility company (usually just utility) is an organization that maintains the infrastructure for a public service (often also providing a service using that infrastructure). Public utilities are subject to forms of public control and regulation ranging from local community-based groups to statewide government monopolies.

Public utilities are meant to supply goods and services that are considered essential; water, gas, electricity, telephone, waste disposal, and other communication systems represent much of the public utility market. The transmission lines used in the transportation of electricity, or natural gas pipelines, have natural monopoly characteristics. A monopoly can occur when it finds the best way to minimize its costs through economies of scale to the point where other companies cannot compete with it. If the infrastructure already exists in a given area, minimal benefit is gained through competing. In other words, these industries are characterized by economies of scale in production. Though it can be mentioned that these natural monopolies are handled or watched by a public utilities commission, or an institution that represents the government.

A communication protocol is a system of rules that allows two or more entities of a communications system to transmit information. The protocol defines the rules, syntax, semantics, and synchronization of communication and possible error recovery methods. Protocols may be implemented by hardware, software, or a combination of both.

Communicating systems use well-defined formats for exchanging various messages. Each message has an exact meaning intended to elicit a response from a range of possible responses predetermined for that particular situation. The specified behavior is typically independent of how it is to be implemented. Communication protocols have to be agreed upon by the parties involved. To reach an agreement, a protocol may be developed into a technical standard. A programming language describes the same for computations, so there is a close analogy between protocols and programming languages: protocols are to communication what programming languages are to computations. An alternate formulation states that protocols are to communication what algorithms are to computation.