WebPart controls are useful for developing portal-type Web sites. Work flow and collaboration management is quickly becoming one of the most important application areas for Web site development. Because portals often have much of the same functionality from one to the other, it makes more sense to build portals from a framework than to build them completely from scratch. Much of this functionality includes such items as file transfers, implementing user profiles, and user administration.
ASP.NET offers three distinct Web Parts development scenarios. These scenarios include (1) building regular pages to consume Web Parts controls, (2) developing Web Parts controls, and (3) implementing Web Parts pages and Web Parts within a portal-type application.
Web Parts controls represent a superset of the existing ASP.NET server-side controls (including rendered controls, User controls, and composite controls) regardless of who wrote them. For maximum programmatic control of your environment, you can also create custom Web Parts controls that derive from the System.Web.UI.WebControls.WebParts.WebPart class.
Regular Web pages may use Web Parts. Visual Studio includes support for creating pages to host WebPart controls. Developing a WebPart page involves introducing a WebPartManager to the page, specifying a number of zones on the page, and then populating them with WebPart controls.
Finally, you may develop entire applications out of WebPart controls. For example, you may decide to build a portal. WebPart controls enable you to write personalized pages that are customizable. Web Parts are also ideal for building a commonly used application (such as sharing records or documentation) and shipping it as a unit so it can be deployed on another company's Web site wholesale.