~~ Video - How to use the Briefcase in Windows
Briefcase is specifically intended for transferring and synchronizing files between separate PCs. Commonly, the Briefcase is carried on a removable disk of some kind, such as a floppy or USB drive; but it also can work on PCs with a direct cable connection or a normal network connection. Briefcase is extremely flexible, and can be useful in almost any situation, from a Fortune 500 enterprise down to a small-office setup, or even for moving data between home PCs.
~~ Video - How to use the Offline folders in Windows
Offline Files is geared more toward transferring and synchronizing network files in instances where a PC is sometimes connected to a network and sometimes not. Rather than using the Briefcase approach of moving between different PCs, Offline Files lets a single PC keep working on local copies of network files even when that PCs disconnected from the network.