Content Index Service gathers all the data on your hard drive, filters it, then catalogs all the resulting words and properties. Content Index Service is also responsible for processing queries to these catalogs and presenting results. Cisvs.exe contains the Change-Notification Component -responsible for alerting Content Index Service to re/index the content/values of files as a result of creating/editing/deleting files. Cisvs.exe contains the Indexing Component -responsible for activating the Filtering-Component and saving the resulting word lists to disk. Cisvs.exe contains the Scanning Component -responsible for detecting file modifiations and is also called when files are on drives that don’t support change notification.