Thus it is advisable to keep the page simple and as brief as possible. Pages that take ten or more minutes to download will not be appreciated. Although most net browsers nowadays are graphical, text only viewers still exist. In addition, most browsers offer the facility to receive text only. This means that pages have to be designed to be usable without graphics.
Many users switch off the graphics facility of their browsers to speed up downloading.
If a large graphic is necessary, then it is advisable to put it in a separate file, and to hyperlink it to the main text. These systems use software similar to those found on the Internet, but are internal to one organisation. Because the whole system, including the choice of communications links, is under the control of the user, the speed limitations mentioned above do not apply, and pages can be much more numerous and detailed. An HTML file is a text file where certain sequences of characters are used as directives to distinguish between headings, separating paragraphs, insertion points for graphics, lists, tables of data, forms for reader interaction and to define hyperlinks. As time passes, other functions, such as background colours, are being added.