For example, if you run a game on your PC, it starts by reading the previously recorded statistics, displaying and altering them as you play the game, and finally writing them back to disk for future reference.
If you run the same game inside the Sandboxie environment, Sandboxie reads the statistics data from the hard disk into the sandbox, to satisfy the read requested by game. When the game later writes the statistics, Sandboxie intercepts this operation and directs the data to the sandbox. If you then run the game without the aid of Sandboxie, the read operation would bypass the sandbox altogether, and the statistics would be retrieved from the hard disk.
Sandboxie version 4 fully supports Windows 8.