W3C Flashcards
HTML and CSS
HTML is the language for describing the structure of Web pages. HTML gives authors the means to:
Publish online documents with headings, text, tables, lists, photos, etc.
Retrieve online information via hypertext links, at the click of a button.
Design forms for conducting transactions with remote services, for use in searching for information, making reservations, ordering products, etc.
Include spread-sheets, video clips, sound clips, and other applications directly in their documents.
CSS is the language for describing the presentation of Web pages, including colors, layout, and fonts. It allows one to adapt the presentation to different types of devices, such as large screens, small screens, or printers. CSS is independent of HTML and can be used with any XML-based markup language. The separation of HTML from CSS makes it easier to maintain sites, share style sheets across pages, and tailor pages to different environments. This is referred to as the separation of structure (or: content) from presentation.
Graphics
Web graphics are visual representations used on a Web site to enhance or enable the representation of an idea or feeling, in order to reach the Web site user. Graphics may entertain, educate, or emotionally impact the user, and are crucial to strength of branding, clarity of illustration, and ease of use for interfaces.
Graphics- PNG
PNG: Portable Network Graphics (PNG) is a static file format for the lossless, portable, well-compressed storage and exchange of raster images (bitmaps). It features rich color control, with indexed-color, grayscale, and truecolor support and alpha-channel transparency
Graphics- SVG
Scalable Vector Graphics (SVG) is like HTML for graphics. It is a markup language for describing all aspects of an image or Web application, from the geometry of shapes, to the styling of text and shapes, to animation, to multimedia presentations including video and audio. It is fully interactive, and includes a scriptable DOM as well as declarative animation (via the SMIL specification). It supports a wide range of visual features such as gradients, opacity, filters, clipping, and masking
Audio and video
The terms audio and video commonly refers to the time-based media storage format for sound/music and moving pictures information. Audio and video digital recording, also referred as audio and video codecs, can be uncompressed, lossless compressed, or lossy compressed depending on the desired quality and use cases.
Audio codecs can usually contain one audio channel (mono), two audio channels (stereo), or more channels (e.g. “5.1” surround). For example, human voice is recorded using one channel while music uses in general two or more channels. The quality will vary depending on the bitrate, ie the number of bits used per unit of playback time.
Video codecs will contain a sequence of frames, ie still pictures and, for compressed formats, movements between those pictures. Quality will vary depending on the number of frames per second, color space, resolution, etc.
Accessibility
The Web is fundamentally designed to work for all people, whatever their hardware, software, language, culture, location, or physical or mental ability. When the Web meets this goal, it is accessible to people with a diverse range of hearing, movement, sight, and cognitive ability.
Thus the impact of disability is radically changed on the Web because the Web removes barriers to communication and interaction that many people face in the physical world. However, when websites, web technologies, or web tools are badly designed, they can create barriers that exclude people from using the Web.
The mission of the Web Accessibility Initiative (WAI) is to lead the Web to its full potential to be accessible, enabling people with disabilities to participate equally on the Web.
Mobile web
The widespread deployment of Web-enabled mobile devices (such as phones) make them a target of choice for content creators. Understanding their strengths and their limitations, and using technologies that fit these conditions are key to create success mobile-friendly Web content.
Ideally, site authors would be able to meet the growing demand for a quality mobile experience without changing a line of code. But the reality is that a site designed specifically with mobility in mind will always provide a much better user experience to mobile users, even when they are equipped with the device du jour.
The reasons for that include the challenges posed by network costs and delays, memory and CPU limitations, keyboard and pointing devices differences. As importantly, they feature a growing set of advantages with their personal and always-available nature, and their increasingly context-aware capabilities.
