A. In the current environment, users are very distributed and may be accessing resources over potentially slow remote office or home links. Typically, when a user accesses a file then accesses it again later, the entire file has to be downloaded again, causing a slow user experience, even if the file hasn't changed since the last time the user read the data.
A new feature called transparent caching is available for Windows 7 that supplements offline files and folders. Transparent caching aggressively stores files in the offline files cache once they've been read. If a user tries to open the same file again, most (if not all) of the file's information can be read from the local cache, saving bandwidth and shortening the time for a user to see the data. This isn't a solution for cases where there's no connectivity—the user's machine still has to talk to the server to find out details about the file to ensure the data it has cached locally isn't stale and out of date.
If this technology sounds familiar, that’s because it's essentially using some of the technology from BranchCache, which allows cross-machine data sharing.