In CSS,
padding is a property that allows the author to specify how
much space will be inserted between the element border and
the element content. Negative values are not allowed.
Paper
Prototype
A paper prototype is a paper sketch of an interface
with just enough detail to make design decisions and
usability evaluations relating to the function and flow of
the interface, not the look.
Persistent
Stylesheet
A Stylesheet that is always applied to the document.
One example is the user agent's Stylesheet: it's always
applied, although you can override it with your own styles.
In Mozilla milestones and builds, this is what the "Basic
Page Style" entry in the "Use Stylesheet" menu
represents.
PHP
PHP is an acronym for PHP hypertext Preprocessor. It is
a server side scripting language for creating dynamic web
pages. This means that it works within an HTML document to confer
to it the capacity of generating content on demand. You can
convert your site into a web application, not just a
collection of static pages. If you've ever seen ASP, you'll
be familiar with embedding code within an HTML page. Like ASP, PHP
script is processed by the Web server. After the server
plays with the PHP code, it returns plain old HTML back to the
browser. This kind of interaction allows for some pretty
complex operations
Pixel
The word "pixel" is derived from "picture element". In
graphics, it refers to smallest resolvable rectangular area
of an image. It is how how monitors divide the display
screen into thousands or millions of individual dots. In
CSS, a pixel is
a relative unit of measure dependent on the viewing device.
They are relative to monitor resolution in contrast to
percent and em that are relative to a browser setting.
Percent and em are considered best practice for
accessibility.
Pixels Per Inch
(PPI)
Pixels Per Inch (PPI) is the resolution of an image
file. Web graphics and screenshots are made up of dots
called pixels, and they usually contain 72 pixels per inch,
though other resolutions are common. The horizontal and/or
vertical density of an operating system's graphical
display, from the point of view of the operating system
(and in turn, of the applications and images running on
it).
Pluralistic
Walkthrough
Pluralistic walkthroughs are when groups of users,
developers, and usability experts walk through a task
scenario. Group walkthroughs have the advantage of
providing a diverse range of skills and perspectives to
bear on usability problems. As with any inspection, the
more people looking for problems, the higher the
probability of finding problems. Also, the interaction
between the team during the walkthrough helps to resolve
usability issues faster.
Plug-in
A module (either hardware or software) that adds a special feature
to a larger system or program. For example, a program
to allow a browser to play movies or to display
Flash content. Plug-ins have accessibility issues.
Portable Document
Format (PDF)
PDF is a proprietary file format developed by Adobe Systems Inc.,
as a way to publish documents electronically, with
good formatting for printing, and document security
(documents are generally read only). Originally
it was in an image format. It was conceived as a
way to make Adobe's Postscript printer language
portable, and it mostly developed along the lines
of press printing document production. Its prevalence
can be attributed to the ease with which one can
create PDF files. It is rare that one finds a PDF
formatted for a computer screen. PDF has accessibility
and usability issues. One of the main problems with
PDF concerns accessibility issues associated with
the document format, but this is only part of the
problem. Even when users have the technology required
to access information presented in this format,
there can be content elements which have not received
appropriate treatment to support accessibility (like
using structural formatting for headings, etc. or
text equivalents for images). Compared to HTML, PDF is slow and cumbersome. Many
applications can save to formats other than their
native file format, such as HTML, so this option when available
is preferable to PDF, even when it needs to be cleaned
up for the web.
Portable Network
Graphics format (PNG)
PNG is an image format was developed as the successor
to the GIF format. It has a more efficient compression
algorithm than GIF.
Preferred
Stylesheet
These style sheets are enabled by default (they are
"on" when the page is loaded). They can then be disabled if
the user selects an alternate style sheet. To make a style
sheet preferred, the rel attribute is set to "stylesheet"
and the style sheet is named with the title attribute.
Pseudo-class
In CSS a pseudo-class is way of selecting certain parts
of a HTML document based in principle not on the HTML
document tree itself and its elements or on characteristics
like name, attributes or contents, but on other phantom
conditions like language encoding or the dynamic state of
an element. The original pseudo-class defined dynamic
states of an element that are entered and exited over time,
or through user intervention. CSS2 expanded on this concept
to include virtual conceptual document components or
inferred portions of the document tree e.g. first-child.
Pseudo-classes operate as if phantom classes were added to
various elements.
Pseudo-element
In CSS pseudo-elements are used to address sub-parts of
elements. They allow you to set style on a part of an
element's content beyond what is specified in the
documents. In other words they allow logical elements to be
defined which are not actually in the document element
tree. Logical elements allow implied semantic structure to
be addressed in CSS selectors.
Presentational Markup
Presentational markup directly describes the way content should be
displayed, rather than its structure or semantics.
It is markup used to control the visual appearance
of a web page in desktop browsers. In contrast structural
markup is used to provide a logical meaning and
structure to a document. Presentation markup is
meaningless outside of a visual medium. The use
of presentation markup is strongly discouraged.
It is generally considered best to separate structural
markup from presentation markup, for several reasons.
It is often useful to apply different presentations
to the same structure, e.g., <font color=red
size=+3> is not useful when I read web
pages on a hand held or other device with a small,
monochrome screen, and it is equally useless to
the vision-impaired user who uses a voice browser.
In fact, if you are in doubt as to whether a certain
piece of markup is structural or presentational,
a good test is to ask "how might that be rendered
in voice."
Primary
Navigation
Primary navigation is the general menu choices that are
repeated on most (if not all) of the pages contained in the
site. It is sometimes called the main menu. Primary
navigation is sometimes referred to as global navigation or
functional navigation. Primary navigation bars provide
shortcuts to main sections on a website.
Progressive Enhancement
Progressive enhancement is a web design strategy which is the opposite
of
graceful degradation. A basic markup document
is created, geared towards the lowest common denominator
of browser software functionality, and then the
designer adds enhancements to the presentation and
behavior of the page, using modern technologies
like Cascading Style Sheets or JavaScript.
Property
In CSS, a
property is named style attribute or parameter for a markup
element specified in a stylesheet declaration, e.g. color,
background, font-family, padding etc., that is assigned a
certain value. Properties are always followed by a colon to
separate them from their value pair. A declaration contains
one or more properties the individual pieces of style to be
applied to the selected element.
Prototype
A prototype is a partially completed mockup of your final website.
Prototyping allows you to test certain parts of
the final website, especially when it is incomplete.
With many sites, this model can be as simple as
paper-and-pencil drawings or as complex as actual
working code.
