Providers are vertical channels that have a single use and can be reused (multiple channels can be created from a single provider) on a custom portal. Providers are Java class files based on the Provider API that can be used to construct both channels and page containers.
You can use the Portal Server pre-built providers such as JSPProvider, URLScraperProvider, and XMLProvider to implement channels without the need to write code.
For more information on the Provider API, see Sun Java System Portal Server 7 Developer’s Guide.