However, if text information is in bitmapped or binary form the search engine cannot read it. This could include graphic items such as pictures, maps, diagrams or program files. You can help the correct indexing of these by including keyword information as metadata, that is, data that is present in the markup language version of the page but that does not normally display. 4.4 Other keywords for searching Words or phrases that a user is likely to use in a search may not in fact appear on a particular page. If this is the case, the words or phrases should be put in the metadata for that page.
Graphic items add life and interest to Web pages.
However they are a major contributor to the size of pages, and can therefore greatly decrease the speed of access. They must be used judiciously. The markup language allows a page developer to designate a line of text to appear as an alternative to a graphic image. People with visual impairment frequently use tools that can interpret text but not graphic images. Many Web users save time and costs by setting their system to not automatically load images.