Telegraph in the context of Strain insulator

Broadcasting is the distribution of audio and audiovisual content to dispersed audiences via an electronic mass communications medium, typically using the electromagnetic spectrum (radio waves), in a one-to-many model. Broadcasting began with AM radio, which became popular around 1920 with the spread of vacuum tube radio transmitters and receivers. Before this, most implementations of electronic communication (early radio, telephone, and telegraph) were one-to-one, with the message intended for a single recipient. The term broadcasting evolved from its use as the agricultural method of sowing seeds in a field by casting them broadly about. It was later adopted for describing the widespread distribution of information by printed materials or by telegraph. Examples applying it to "one-to-many" radio transmissions of an individual station to multiple listeners appeared as early as 1898.

Over-the-air broadcasting is usually associated with radio and television, though more recently, both radio and television transmissions have begun to be distributed by cable (cable television). The receiving parties may include the general public or a relatively small subset; the point is that anyone with the appropriate receiving technology and equipment (e.g., a radio or television set) can receive the signal. The field of broadcasting includes both government-managed services such as public radio, community radio and public television, and private commercial radio and commercial television. The U.S. Code of Federal Regulations, title 47, part 97 defines broadcasting as "transmissions intended for reception by the general public, either direct or relayed". Private or two-way telecommunications transmissions do not qualify under this definition. For example, amateur ("ham") and citizens band (CB) radio operators are not allowed to broadcast. As defined, transmitting and broadcasting are not the same.

Telecommunication, often used in its plural form or abbreviated as telecom, is the transmission of information over a distance using electrical or electronic means, typically through cables, radio waves, or other communication technologies. These means of transmission may be divided into communication channels for multiplexing, allowing for a single medium to transmit several concurrent communication sessions. Long-distance technologies invented during the 20th and 21st centuries generally use electric power, and include the electrical telegraph, telephone, television, and radio.

Early telecommunication networks used metal wires as the medium for transmitting signals. These networks were used for telegraphy and telephony for many decades. In the first decade of the 20th century, a revolution in wireless communication began with breakthroughs including those made in radio communications by Guglielmo Marconi, who won the 1909 Nobel Prize in Physics. Other early pioneers in electrical and electronic telecommunications include co-inventors of the telegraph Charles Wheatstone and Samuel Morse, numerous inventors and developers of the telephone including Antonio Meucci, Philipp Reis, Elisha Gray and Alexander Graham Bell, inventors of radio Edwin Armstrong and Lee de Forest, as well as inventors of television like Vladimir K. Zworykin, John Logie Baird and Philo Farnsworth.

An office is a space where the employees of an organization perform administrative work in order to support and realize the various goals of the organization. The word "office" may also denote a position within an organization with specific duties attached to it (see officer or official); the latter is an earlier usage, as "office" originally referred to the location of one's duty. In its adjective form, the term "office" may refer to business-related tasks. In law, a company or organization has offices in any place where it has an official presence, even if that presence consists of a storage silo. For example, instead of a more traditional establishment with a desk and chair, an office is also an architectural and design phenomenon, including small offices, such as a bench in the corner of a small business or a room in someone's home (see small office/home office), entire floors of buildings, and massive buildings dedicated entirely to one company. In modern terms, an office is usually the location where white-collar workers carry out their functions.

In classical antiquity, offices were often part of a palace complex or a large temple. In the High Middle Ages (1000–1300), the medieval chancery acted as a sort of office, serving as the space where records and laws were stored and copied. With the growth of large, complex organizations in the 18th century, the first purpose-built office spaces were constructed. As the Industrial Revolution intensified in the 18th and 19th centuries, the industries of banking, rail, insurance, retail, petroleum, and telegraphy grew dramatically, requiring many clerks. As a result, more office space was assigned to house their activities. The time-and-motion study, pioneered in manufacturing by F. W. Taylor (1856–1915), led to the "Modern Efficiency Desk" of 1915. Its flat top, with drawers below, was designed to allow managers an easy view of their workers. By the middle of the 20th century, it became apparent that an efficient office required additional control over privacy, and gradually the cubicle system evolved.

The Rhodes Colossus is an editorial cartoon illustrated by the English cartoonist Edward Linley Sambourne and published by Punch magazine in 1892. It depicts the English business magnate Cecil Rhodes as a giant straddling over Africa and holding a telegraph line grounded at the northern and southern ends of the continent, a reference to his desire to build a "Cape to Cairo" rail and telegraph line connecting most of the British colonies in Africa. It is a visual pun on the Colossus of Rhodes, one of the Seven Wonders of the Ancient World.

A postal, telegraph, and telephone service (or PTT) is a government agency responsible for postal mail, telegraph, and telephone services. Such monopolies existed in many countries, though not in North America, post-war Japan or Spain. Many PTTs have been partially or completely privatised in recent years, though a few, such as Posta ve Telgraf Teşkilatı of Turkey, Myanma Posts and Telecommunications of Myanmar and Tusass of Greenland, continue to remain wholly government-owned. In many of said privatisations, the privatised corporation was completely renamed, such as KPN in the Netherlands, Orange S.A. in France (+ Orange Polska in Poland), BT Group in the United Kingdom, Eir in the Republic of Ireland, Swisscom in Switzerland, Telstra in Australia, Spark in New Zealand, Proximus Group in Belgium, A1 Telekom Austria Group in Austria, TDC Group in Denmark, Telia Company in Sweden and Finland, Telenor in Norway, Chunghwa Telecom in Taiwan and Singtel in Singapore; whereas in others, the name of the privatised corporation has been only slightly modified, such as Telkom Indonesia in Indonesia, Telekom Malaysia in Malaysia, Deutsche Telekom in Germany (+ Hrvatski Telekom in Croatia and Telekom Romania Mobile in Romania), Kosovo Telecom in Kosovo, KT in South Korea, Post Luxembourg in Luxembourg and Síminn in Iceland.

In telecommunications, the term terminal equipment has the following meanings:

• Communications equipment at either end of a communications link, used to permit the stations involved to accomplish the mission for which the link was established.
• In radio-relay systems, equipment used at points where data are inserted or derived, as distinct from equipment used only to relay a reconstituted signal.
• Telephone and telegraph switchboards and other centrally located equipment at which communications circuits are terminated.

Industrial warfare is a period in the history of warfare ranging roughly from the early 19th century and the start of the Industrial Revolution to the beginning of the Atomic Age, which saw the rise of nation-states, capable of creating and equipping large armies, navies, and air forces, through the process of industrialization.

The era featured mass-conscripted armies, rapid transportation (first on railroads, then by sea and air), telegraph and wireless communications, and the concept of total war. In terms of technology, this era saw the rise of rifled breech-loading infantry weapons capable of high rates of fire, high-velocity breech-loading artillery, chemical weapons, armoured warfare, metal warships, submarines, and aircraft.

Electrical telegraphy is point-to-point distance communicating via sending electric signals over wire, a system primarily used from the 1840s until the late 20th century. It was the first electrical telecommunications system and the most widely used of a number of early messaging systems called telegraphs, that were devised to send text messages more quickly than physically carrying them. Electrical telegraphy can be considered the first example of electrical engineering.

Electrical telegraphy consisted of two or more geographically separated stations, called telegraph offices. The offices were connected by wires, usually supported overhead on utility poles. Many electrical telegraph systems were invented that operated in different ways, but the ones that became widespread fit into two broad categories. First are the needle telegraphs, in which electric current sent down the telegraph line produces an electromagnetic force that moves a needle-shaped pointer into position over a printed list, in order to point to a specific item in that list (such as a letter of the alphabet). Early needle telegraph models used multiple needles, thus requiring multiple wires to be installed between stations. The first commercial needle telegraph system and the most widely used of its type was the Cooke and Wheatstone telegraph, invented in 1837. The second category are armature systems, in which the current activates a telegraph sounder that makes a click; communication on this type of system relies on sending clicks in coded rhythmic patterns. The archetype of this category was the Morse system and the code associated with it, both invented by Samuel Morse in 1838. In 1865, the Morse system became the standard for international communication, using a modified form of Morse's code that had been developed for German railways.

A beacon is an intentionally conspicuous device designed to attract attention to a specific location. A common example is the lighthouse, which draws attention to a fixed point that can be used to navigate around obstacles or into port. More modern examples include a variety of radio beacons that can be read on radio direction finders in all weather, and radar transponders that appear on radar displays.

Beacons can also be combined with semaphoric or other indicators to provide important information, such as the status of an airport, by the colour and rotational pattern of its airport beacon, or of pending weather as indicated on a weather beacon mounted at the top of a tall building or similar site. When used in such fashion, beacons can be considered a form of optical telegraphy.

The Panic of 1857 was a financial crisis in the United States caused by the declining international economy and over-expansion of the domestic economy. Because of the invention of the telegraph by Samuel F. Morse in 1844, the Panic of 1857 was the first financial crisis to spread rapidly throughout the United States. The world economy was more interconnected by the 1850s, which made the Panic of 1857 the first worldwide economic crisis. In Britain, the Palmerston government circumvented the requirements of the Bank Charter Act 1844, which required gold and silver reserves to back up the amount of money in circulation. Surfacing news of this circumvention set off the Panic in Britain.

Beginning in September 1857, the financial downturn did not last long, but a proper recovery was delayed until the onset of the American Civil War in 1861. The sinking of SS Central America in September 1857 contributed to the panic, because New York City banks were waiting on its much-needed shipment of gold. After the failure of Ohio Life Insurance and Trust Company, the financial panic quickly spread with businesses beginning to fail, the railroad industry experiencing financial declines, and hundreds of thousands of workers being laid off.

An optical telegraph is a line of stations, typically towers, for the purpose of conveying textual information by means of visual signals (a form of optical communication). There are two main types of such systems: the semaphore telegraph which uses pivoted indicator arms and conveys information according to the direction the indicators point, and the shutter telegraph which uses panels that can be rotated to block or pass the light from the sky behind to convey information.

The most widely used system was the Chappe telegraph, which was invented in France in 1792 by Claude Chappe. It was popular in the late eighteenth to early nineteenth centuries. Chappe used the term télégraphe to describe the mechanism he had invented – that is the origin of the English word "telegraph". Lines of relay towers with a semaphore rig at the top were built within line of sight of each other, at separations of 5–20 miles (8–32 km). Operators at each tower would watch the neighboring tower through a telescope, and when the semaphore arms began to move spelling out a message, they would pass the message on to the next tower.

The telegrapher's equations (or telegraph equations) are a set of two coupled, linear partial differential equations that model voltage and current along a linear electrical transmission line. The equations are important because they allow transmission lines to be analyzed using circuit theory. The equations and their solutions are applicable from 0 Hz (i.e. direct current) to frequencies at which the transmission line structure can support higher order non-TEM modes. The equations can be expressed in both the time domain and the frequency domain. In the time domain the independent variables are distance and time. In the frequency domain the independent variables are distance ${\displaystyle x}$ and either frequency, ${\displaystyle \omega }$, or complex frequency, ${\displaystyle s}$. The frequency domain variables can be taken as the Laplace transform or Fourier transform of the time domain variables or they can be taken to be phasors in which case the frequency domain equations can be reduced to ordinary differential equations of distance. An advantage of the frequency domain approach is that differential operators in the time domain become algebraic operations in frequency domain.

The equations come from Oliver Heaviside who developed the transmission line model starting with an August 1876 paper, On the Extra Current. The model demonstrates that the electromagnetic waves can be reflected on the wire, and that wave patterns can form along the line. Originally developed to describe telegraph wires, the theory can also be applied to radio frequency conductors, audio frequency (such as telephone lines), low frequency (such as power lines), and pulses of direct current.

An electronic signature, or e-signature, is data that is logically associated with other data and which is used by the signatory to sign the associated data. This type of signature has the same legal standing as a handwritten signature as long as it adheres to the requirements of the specific regulation under which it was created (e.g., eIDAS in the European Union, NIST-DSS in the USA or ZertES in Switzerland).

Electronic signatures are a legal concept distinct from digital signatures, a cryptographic mechanism often used to implement electronic signatures. While an electronic signature can be as simple as a name entered in an electronic document, digital signatures are increasingly used in e-commerce and in regulatory filings to implement electronic signatures in a cryptographically protected way. Standardization agencies like NIST or ETSI provide standards for their implementation (e.g., NIST-DSS, XAdES or PAdES). The concept itself is not new, with common law jurisdictions having recognized telegraph signatures as far back as the mid-19th century and faxed signatures since the 1980s.