1. Portal serves as a WEB site on the Internet as a gateway. Portal is a collection of links, content, and guidance services that provide information that users may find of interest (such as news, weather, entertainment, business sites, chat rooms, etc.). Yahoo, Excite, MSN.com and Netscape NetCenter are all Portals.
2. In fantasy games, science fiction and some "new era" philosophies, a portal is a passage into another world in the past, present or future, or into an expanded understanding.
3. In 3D graphics development, Portal is a technology that increases the effect of realism and accelerates display.