Offline Files is the single most useful Windows feature you’ve never heard of. It first appeared in Windows XP, but it was greatly improved in Windows Vista and has been refined even more for Windows 7.
The idea is simple. From a PC running a business version of Windows (sorry, not available in Home Basic or Home Premium), you connect to a network computer. You find a network share or shared folder on another computer, right-click, and click Always Available Offline.
That creates a sync partnership, and Windows immediately begins creating a local cache of the files in the remote folder. As long as you’re connected to the network, you work with the remote files directly, and Windows updates the local cache with your changes. When you disconnect from the network, you can still open the shared folder using a mapped drive or a UNC name (\\server\share), but you’re working with the cached files. You can create new files and folders, edit and save existing files, or delete objects. When you reconnect to the network, your changes are synced up using the settings you define.
The remote location doesn’t have to be running Windows either. I’ve successfully configured shares on a PC running Ubuntu Linux for offline access, and I have no doubt that connecting to a Mac file share would work as well, since it also uses Samba.
Of course, when you work with files in two different locations, you run the risk of making changes to the same file in each location. That contingency is handled very well by the sync engine, which detects conflicts and allows you to resolve them by choosing one of the conflicting files or keeping both (giving a new name to the older file in the process).
The best part about this feature is that it eliminates the frantic scramble to sync files from desktop to notebook before a business trip. In my office, I keep all working files in a shared folder on an HP MediaSmart Home Server. I have the notebook set for offline access to the work files and to my Photos share, so I know I’ll always have up-to-date copies of those files in at least two places. Read original artical by Ed Bott here.