Color, typography, illustration and interaction

Webpages usually include information as to the colors of text and backgrounds and very often also contain links to images and sometimes other media to be included in the final view.

Layout, typographic and color-scheme information is provided by Cascading Style Sheet (CSS) instructions, which can either be embedded in the HTML or can be provided by a separate file, which is referenced from within the HTML. The latter case is especially relevant where one lengthy stylesheet is relevant to a whole website: due to the way HTTP works, the browser will only download it once from the web server and use the cached copy for the whole site.

Images are stored on the web server as separate files, but again HTTP allows for the fact that once a webpage is downloaded to a browser, it is quite likely that related files such as images and stylesheets will be requested as it is processed. An HTTP 1.1 web server will maintain a connection with the browser until all related resources have been requested and provided. Web browsers usually render images along with the text and other material on the displayed webpage.

Dynamic behavior

Main article: dynamic web page

Client-side computer code such as JavaScript or code implementing Ajax techniques can be provided either embedded in the HTML of a webpage or, like CSS stylesheets, as separate, linked downloads specified in the HTML. These scripts may run on the client computer, if the user allows them to, and can provide additional functionality for the user after the page has downloaded.

Browsers

A web browser can have a Graphical User Interface, like Internet Explorer, Mozilla Firefox and Opera, or can be text-based, like Lynx.

Web users with disabilities often use assistive technologies and adaptive strategies to access webpages.^[1] Users may be color blind, may or may not want to use a mouse perhaps due to repetitive stress injury or motor-neurone problems, may be deaf and require audio to be captioned, may be blind and using a screen reader or braille display, may need screen magnification, etc.

Disabled and able-bodied users may disable the download and viewing of images and other media, to save time, network bandwidth or merely to simplify their browsing experience. Users of mobile devices often have restricted displays and bandwidth. Anyone may prefer not to use the fonts, font sizes, styles and color schemes selected by the webpage designer and may apply their own CSS styling to the page.

The World Wide Web Consortium (W3C) and Web Accessibility Initiative (WAI) recommend that all webpages should be designed with all of these options in mind.