Web Technology and Multimedia
What this domain tests
You must write and read small HTML documents, apply basic CSS, distinguish static from dynamic pages and client-side from server-side scripting, and handle multimedia file formats and size calculations.
Core rules
- The Internet is the physical network; the WWW is a service over it. A URL has a protocol, domain, optional port and path, for example https://school.edu/admission/form.html.
- HTML page skeleton: DOCTYPE, html, head with title, then body. Presentational tags: h1-h6, p, br, hr; links use a href, images use img src with alt text; lists use ul/ol/li; tables use table, tr, th, td; forms use form and input.
- HTML is a markup language, not a programming language; it structures content.
- CSS: inline style attribute, internal style element in head, external .css file linked with link rel="stylesheet". Selectors: element, .class, #id; inline beats internal beats external for equal specificity.
- Static pages send the same file every time; dynamic pages are generated by server-side scripts such as PHP or ASP, while JavaScript runs in the browser.
- Multimedia combines text, graphics, audio, video and animation. Raster images store pixels; vector images store geometric instructions. JPEG, MP3 and MP4 are lossy; PNG, GIF and WAV are lossless.
Worked example
An uncompressed 640 x 480 image at 24-bit colour needs 640 x 480 pixels = 307200 pixels; at 3 bytes per pixel the size is 307200 x 3 = 921600 bytes, about 900 KB. Storing it as JPEG shrinks the file by discarding detail the eye barely notices.
Traps that cost marks
- Writing img with a closing tag, or giving src where href belongs on a link.
- Leaving out alt text on images.
- Saying HTML is a programming language.
- Calling JPEG lossless.
- Mixing up client-side JavaScript with server-side PHP.