Transcribed from Mohammed Malik's blog, 18 March 2011
What does XMP sidecar mean? It means that when ever metadata is written to an image, an XMP file is created along-side the image. Therefore instead of writing the metadata to the image a new XMP file is created, which is linked to the image.
If a picture has the name mohamedmalik.JPG, when metadata is written to the image it will create a new file in the same directory called mohamedmalik.JPG.XMP. This file contains all the new and previously written metadata, leaving the image untouched. This is very useful when writing metadata to RAW files.
While using XMP sidecar support there are many options available. In-order to use XMP sidecar support you need to configure it.
In digiKam’s main window go toand select the tab
There are four options available: