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Trust in ICT 2
language that web browsers use to interpret and compose text, images and other materials into web pages.
Web browsers can read HTML files and render them into visible or audible web pages. HTML describes the
structure of a website semantically for presentation, making it a markup language, rather than
a programming language. The HTML elements form the building blocks of all websites. HTML allows images
and objects to be hyperlinked and can be used to create interactive forms. It provides a means to create the
structured documents by denoting structural semantics for texts such as headings, paragraphs, lists, links,
quotes, and other items. The language is written in the form of HTML elements consisting of tags enclosed
in angle brackets like <html>. Browsers do not display the HTML tags and scripts, but use them to interpret
the contents of the page. HTML can include scripts languages such as JavaScript which affect the behaviours
of HTML web pages. Web browsers can also refer to cascading style sheets (CSS) to define the look and layout
of texts and other materials.
If the metadata is stored in HTML format, it is very easy to share on the Internet. The files
representing metadata can be grouped into three parts: structured texts from reference points to data, how
the files can be accessed, and location information of files. HTML prescribes how the text will be formatted
visually, which fonts will be used and on which place, where the image will be situated, and where the
heading of the chapter is located, etc. However, it is typical for the descriptions of the documents that they
can be classified into various categories. These categories form a certain hierarchy depending on their
significance. The differences of content are not always represented visually in formatted documents, but
they are very important for the mass processing of metadata.
The data models described above are summarized as follows:
• Entity-attribute-value (EAV) models
– Making statements about resources.
– (Examples) XML document type definition (DTD), tag, name, address, etc.
• Data serialization models
– File, memory buffer, packets of communication protocol, and time-varying data, etc.
– (Examples) binary/integer/real/exponent/character/string/Boolean/time,
vector/matrix/array, 2D/3D graphics, recursive, audio/video stream, etc.
• Metadata/schema/markup data models
– Specify the processing to be performed or the related actions (i.e. layout, activate, trigger, and
invoke, etc.).
Data storage
There was a long history of writing, recording, and storing information. Recording can be done using virtually
any form of energy, spanning from manual muscle power in handwriting, to acoustic vibrations
in phonographic recording, to electromagnetic energy modulating magnetic tape and optical discs. A storage
device may hold information. Electronic data storage requires electrical power to store and retrieve data.
Electromagnetic data may be stored in either an analogue data or digital data on a variety of media. This type
of data is considered to be electronically encoded data, whether it is electronically stored in
a semiconductor device. Most electronically processed data storage media (including forms of digital data)
are considered permanent (non-volatile) storage, that is, the data will remain stored when power is removed
from the device. In contrast, most electronically stored information is volatile memory while it vanishes if
power is removed.
Except for printed data, electronic data storage is easier to revise and may be more cost effective than
alternative methods due to smaller physical space requirements and the ease of replacing (rewriting) data
on the same medium. However, the durability of printed data is still superior to that of most electronic
storage media. The durability limitations may be overcome by the ease of duplicating (backing-up) electronic
data. In this digital age, the long-term durability may be more significant since more than several zeta-bytes
of the storage capacity may be needed within few years.
The information files stored on millions of servers constitute educational, cultural, and scientific resources.
"Web culture" is characterized by the extreme rapidity of data-flows and rapid obsolescence. The average
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