Non-experienced users of a Synology DiskStation (NAS) have the possibility to use the package management option to update their system with other programs and possibilities. A special kind of package baring the extension .spk is used to do this update.
An .spk file is nothing more then a tar file, containing a standard structure and files. Every package will contain an INFO file, a compressed (gzip) tar file package.tgz and a directory scripts containing multiple shell scripts.
The file can be easily installed in the Synology DashBoard with the Package Center.
More informations about .spk packages are available at the following links :