Television is a medium for transmitting moving images and sound through telecommunication technologies. Early television used optical and mechanical technologies but modern television relies on electronic technologies to capture images and transmit them as a stream of electrical pulses using scanning. The first transmitted images were sent electrically in the late 19th century by early fax machines. Television programming can be distributed through original broadcast runs on networks or stations or later syndication to other markets and stations. Television worldwide is financed through various means including government, advertising, licensing fees or subscriptions.
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2. ï‚ž levision (TV) is
a telecommunication medium for transmitting
and receiving moving images that can
be monochrome (black-and-white) or colored,
with or without accompanying sound.
"Television" may also refer specifically to
a television set, television programming,
or television transmission.
ï‚ž The etymology of the word has a mixed Latin
and Greek origin, meaning "far sight":
Greek tele (τῆλε), far, and Latin visio, sight
(from video, vis- to see, or to view in the first
person).
3. ï‚ž In its early stages of development, television
employed a combination of optical,
mechanical and electronic technologies to
capture, transmit and display a visual
image. By the late 1920s, however, those
employing only optical and electronic
technologies were being explored. All
modern television systems relied on the
latter, although the knowledge gained from
the work on electromechanical systems
was crucial in the development of fully
electronic television.
4. ï‚ž The first images transmitted electrically were
sent by early mechanical fax machines,
including the pan telegraph, developed in
the late nineteenth century. The concept of
electrically powered transmission of
television images in motion was first
sketched in 1878 as the telephonoscope,
shortly after the invention of the telephone.
At the time, it was imagined by early
science fiction authors, that someday that
light could be transmitted over copper
wires, as sounds were.
5. ï‚ž he idea of using scanning to transmit
images was put to actual practical use in
1881 in the pantelegraph, through the use
of a pendulum-based scanning
mechanism. From this period forward,
scanning in one form or another has been
used in nearly every image transmission
technology to date, including television.
This is the concept of "rasterization", the
process of converting a visual image into a
stream of electrical pulses.
6. ï‚ž Getting TV programming shown to the public can happen in
many different ways. After production the next step is to market
and deliver the product to whatever markets are open to using
it. This typically happens on two levels:
ï‚ž Original Run or First Run: a producer creates a program of one or
multiple episodes and shows it on a station or network which has
either paid for the production itself or to which a license has
been granted by the television producers to do the same.
ï‚ž Broadcast syndication: this is the terminology rather broadly used
to describe secondary programming usages (beyond original
run). It includes secondary runs in the country of first issue, but
also international usage which may not be managed by the
originating producer. In many cases other companies, TV
stations or individuals are engaged to do the syndication work, in
other words to sell the product into the markets they are allowed
to sell into by contract from the copyright holders, in most cases
the producers.
7. ï‚ž Around the globe, broadcast television is
financed by either government,
advertising, licensing (a form of tax),
subscription or any combination of
these. To protect revenues, subscription
TV channels are usually encrypted to
ensure that only subscription payers
receive the decryption codes to see the
signal. Unencrypted channels are known
as free to air or FTA.
8. ï‚ž Television's broad reach makes it a
powerful and attractive medium for
advertisers. Many television networks
and stations sell blocks of broadcast time
to advertisers ("sponsors") in order to fund
their programming
9. ï‚ž Since inception in the U.S. in 1940[citation
needed], television commercials have become
one of the most effective, persuasive, and
popular methods of selling products of many
sorts, especially consumer goods. During the
1940s and into the 1950s, programs were
hosted by single advertisers. This, in turn, gave
great creative license to the advertisersover
the content of the show. Due to[citation
needed] the quiz show scandals in the 1950s,
networks shifted to the magazine concept
introducing advertising breaks with multiple
advertisers.