By batching separate method calls, i.e. transforming them into a single cross-domain call, one can avoid unnecessary data copying and reduce the number of cross-domain calls.
Clients can build a program (a ``batch call'') and transfer it to the server at once. The program performs multiple operations on that server even though the client had to send it only once.
In our example (see figure 2, the interactions for cat), if BATCHING is not used, the file content has to travel twice across the network. When a cat program is submitted to the server, however, the file does not leave the server, it is copied locally.