File with an .XMP extension contains metadata of edited RAW image files stored in a text format next to them. If we do not want to have an XMP generated for every NEF or CR2 file, it can be stored also in the DNG format which has an XMP file built in. Data stored within the XMP file may be related to its graphical properties (exposure, brightness setting, contrast or saturation), or it may contain information on copyrights, keywords, descriptions or author and also many other parameters.

The XMP format was developed by Adobe in order to standardize storing metadata in different types of files. It is used mainly by Adobe software, such as Photoshop or Bridge, in order to store metadata of raw photographs. If such file is deleted, we may lose all the changes made in Adobe software. Metadata contained in XMP files can be viewed in a standard text editor.