Lets say you have a USB-Stick for your car entertainment system plus an Android device. Sure you want to have some music in your car and on your Android. But your car only accepts MP3 and needs a special folder-layout while your Android device plays many formats, but you want to save space and therefore want lower bitrates. And at least you want to have different albums and playlists in your car then on your Android. FoobarSync will help you to meet those demands plus more.
FoobarSync will get a subset of items from your Medialibrary AND your playlists, defined by a search-query and other rules. The selected items can be defined per target (one configuration file per target). This configuration file is stored in the root folder of the target. When synchronizing each item is checked against the defined rule sets and then a) copied to the target or b) converted to the target. If your subset (choosen items) in foobar2000 changes, these changes will get synchonized as soon as you rerun FoobarSync.