Part of the indexing process used by the Microsoft Indexing Service, an optional component of Microsoft Windows 2000 Server. In Microsoft Windows NT, scanning is made available through Microsoft Index Server. Scanning is the process of inventorying virtual directories on the server that have been configured for indexing to determine whether any new documents have been added that need to be indexed.
Scanning can take two forms:
If either type of scan finds documents that need to be indexed, the documents are passed to content filters that extract indexing information to form volatile indexes called word lists. This process is called filtering.
Various conditions can trigger a scan of a virtual directory: