Just as there are occasions when you want to transfer data to a host where it can be processed, there are also occasions when you want to process the data where it exists and send the processing results to another host. The data sets or files could be too large to transfer efficiently or all the data might be kept at one host for security reasons. The computing power necessary to perform some tasks could be more than your host is capable of or the only licensed copy of a required program might reside at some other host. TCP⁄IP provides a command that enables you to use the processing resources of other hosts. The TSO commands REXEC and RSH and the z/OS® UNIX shell command orexec run client programs that enable you to send any command that is valid in the remote host shell environment and receive the results at the local host. The remote host must be running a rexec server, an rsh server, or both. A user ID and password provide security checking at the remote host. The command sent to the remote host must not require user interaction to complete. See z/OS Communications Server: IP System Administrator's Commands for more information about these commands.