A collector can be configured to extract data from a specific source, and returns the content to explorer for indexing.
To make use of a collector, you must first make sure it is installed. Collectors are typically distributed as regular XP applications, but Explorer also ships with a standard collector called webcrawler.
To make use of a collector, you must first create a collection, then choose the specific collector and configure it.
All items returned from the collector will then be stored and indexed in the specific collection.
For each collection, Explorer will run the specified collector as a background job. The jobs follow the defined schedule of the collection.