WORLD WIDE WEB
The World Wide Web (www, W3) is an information system of interlinked hypertext documents that are accessed via the Internet. It has also commonly become known simply as the Web. Individual document pages on the World Wide Web are called web pages and are accessed with a software application running on the user's computer, commonly called a web browser. Web pages may contain text, images, videos, and other multimedia components, as well as web navigation features consisting of hyperlinks.
Performed by: Santiago Londoño.
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VOLATILE.
Statistical unit indicating the tendency to
have changes in a certain period of time.
Video: https://youtu.be/L8c-J05gnPs
Performed by: Mateo Quiceno.
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VARIABLE.
The use of variables, as in mathematics, allows you to refer to a
certain number by a label that identifies it. Given that the content of the tag
is modifiable, are used to store results, or to temporarily save changing
values.
There are different types of vriables:
- · Variable alphanumeric:
- · Contadora Variable:
Variable that controls the
iterations of a loop of programming.
- Global Variable:
Variable that can be used at any point of the
program without losing their content.
- · Local Variable:
Variable that can only be used in certain
routines and that loses its value when the execution of the program comes out
of these.
- · Numeric Variable:
Variable that can contain
only numeric values. Numeric variables can be whole, real or double precision.
- · Variable signed:
variable that is defined by
its name and one or more indexes to indicate their relative position within the
whole.
Performed by: Clara Estephania Arias.
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UPS (uninterruptible power supply).
An uninterruptible
power supply, also uninterruptible power source, UPS or battery/flywheel
backup, is an electrical apparatus that provides emergency power to a load when
the input power source, typically mains power, fails. A UPS differs from an
auxiliary or emergency power system or standby generator in that it will
provide near-instantaneous protection from input power interruptions, by
supplying energy stored in batteries, supercapacitors, or flywheels. The
on-battery runtime of most uninterruptible power sources is relatively short
(only a few minutes) but sufficient to start a standby power source or properly
shut down the protected equipment.
A UPS is typically
used to protect hardware such as computers, data centers, telecommunication
equipment or other electrical equipment where an unexpected power disruption
could cause injuries, fatalities, serious business disruption or data loss. UPS
units range in size from units designed to protect a single computer without a
video monitor (around 200 volt-ampere rating) to large units powering entire
data centers or buildings. The world's largest UPS, the 46-megawatt Battery
Electric Storage System (BESS), in Fairbanks, Alaska, powers the entire city
and nearby rural communities during outages.
Common power
problems:
The primary role of
any UPS is to provide short-term power when the input power source fails.
However, most UPS units are also capable in varying degrees of correcting
common utility power problems:
- Voltage spike or sustained overvoltage
- Momentary or sustained reduction
in input voltage
- Noise, defined as a high frequency transient or oscillation, usually injected into the line by nearby
equipment
- Instability of the mains frequency
- Harmonic
distortion:
defined as a departure from the ideal sinusoidal waveform expected on the line
UPS units are divided
into categories based on which of the above problems they address, and some
manufacturers categorize their products in accordance with the number of
power-related problems they address.
Performed by: Yulisa Gonzáles.
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URL
(uniform resource locator).
It serves to name resources
on the Internet. This name has a standard format and is intended to assign a
unique address to each of the resources available on the Internet, for example
texts, images, videos, etc.
URL format:
A URL has a standard format, is: scheme: / / machine/directory/file.
For example, for
http://aprenderinternet.about.com/bio/Luis-Castro-90589.htm: scheme is http,
the machine is aprenderinternet.about.com, the directory is bio and the file is
Luis-Castro - 90589.htm.
URL scheme:
A scheme serves for purposes of classification.
Specified in a URL before the colon. The specification of the elements that
follow after the colon varies depending on the scheme. Some examples are
commonly found in the daily use of the Internet:
- Http, which is the most frequently found scheme when surfing on the Internet.
- HTTPS, which is the scheme used to secure Internet, known as SSL pages.
- Mailto, schema used for e-mail addresses.
- FTP (File Transfer Protocol), scheme used for the ftp file transfer protocol.
Performed by: Santiago Alvarez.
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USER.
A user
who uses is ordinarily something. It referred to the person who uses any type
of object or it is the beneficiary of a service, either private or public. For
example: users of telecommunications we have the right to claim to the
attendants the fulfillment that promise in their promotions
The
notion of user is very popular in the field of informatics. In this sense, a
user can be both a person such as a computer or an application, since the
concept is linked to the access to certain resources or devices.
video: none
Performed by: Julian Alzate Hurtado
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