The file format for runtimes is exactly the same as that created by Pro/advanced. If by "sync" you want to pull data from one to the other, it's very easy to use FileMaker Pro/advanced to import data from the runtime files. To use the runtime to import data from a file not "bound" to the runtime file will be a problem, but if you export the data into a merge or other text file, the runtime can import it.
Not exactly what i meant...
I will use an iPad to gather data offsite, and when I return I want the data on the iPad to be transfered and updated on the computer and also when when i go away I want the data from the computer to be the same on the iPad ( by command that is, like sync database-files )
So, do the one on the computer be a server-version, normal version or can it be a standalone runtime version?
You don't put runtime systems on an iOS device such as an iPad. You just put the regular FileMaker File on it and open it in FileMaker Go. FileMaker Advanced is not required for that process.
"Synching" data between two Filemaker files (whether Go or Pro or Advanced) can be very simple for simple files and usage patterns or very complex if you have many different tables, many different users, all using different copies of the data to modify different records in different ways.
If you are the only user of the database, the simplest way to "synch" is just to copy the file back and forth between devices. If one user may modify data on the computer at the same time that another user may modify data on the iPad, then you have a more complex situation. It is possible to create your own synch system. See this PDF on the topic: http://www.filemaker.com/solutions/ios/docs/fmi_guide_sync_en.pdf
And both 360Works and SeedCode offer 3rd party tools that do the Synch for you.
Ah, now I get it, and a great PDF to read as well, I had missed that one.