Navigational icons are anchors which are always highlighted on the user's screen. Identification icons are not anchors, and are therefore not highlighted. Identification icons are in-line images, such as letterheads, logos, or running heads, which are used for identity on hypertext landing pages. It can be particularly helpful to create identification icons for all landing pages and then to use the same icon as an anchor from other pages to that landing page. In some instances it will be appropriate to shrink or crop an identification icon to make it a useful navigational icon.
Navigational icons are in-line images used as anchors to landing pages.
By labeling icons within the image box, you differentiate them from those in-line images which are anchors, but not icons. In-line images can be active anchors without being icons. For instance, an in-line image may connect the user to an enlargement of the image, or to a textual description of some aspect of the image. In this case, an image is merely a hypertextual link. You should also remember that image files are generally much larger than text files.