If you asked ten people the definition of a portal, you might very well get ten different answers. Because no two portal implementations are alike, SharePoint Server 2007 provides a customizable and extensible foundation to make your portal unique and applicable in your environment. The ultimate goal of any portal is to create a single place for people to visit that offers a high probability that they can find what they are looking for. No matter how you design your portal, you should focus on aggregating and organizing information. Aggregated and organized information lends itself to being referenced quickly and used frequently. Information managed by a portal becomes more valuable because it can be targeted to specific audiences and therefore most likely will be used more frequently.
In SharePoint Server, portals are created by applying the Collaboration or Publishing Portal templates when creating a site collection. The Collaboration Portal template is intended for creating corporate Intranet portals. The Publishing Portal provides a robust framework for creating an Internet presence. A collaborative portal is a single location in which information is used and shared among many users. Large organizations may benefit from multiple collaborative portals that are dedicated to specific functions and are linked to a central, less collaborative portal that serves as a hub for locating information. The use of multiple portals may be indicated for different geographic regions, organizational units, or for legal or regulatory purposes.