SDF, Standard Data File (.sdf)
The SDF Data file format
SDF files are used to store databases in a structured format. It's a generic or standard file extension that is not associated with a certain program or database version. Thus, the files can be easily imported and exported by a vast number of database programs.
Technical details of SDF files
The database information contained in the SDF file consists of fields with a fixed length. These fields can contain different values. The most common usage of such a generic file format is to exchange data between two programs. That way, only the values inside the database are saved and transferred without leading to complications with the compatibility of different programs.