The Windows NT command processor allows you to specify more than one command on the command prompt line by using the ampersand character as a command separator. For example, the following command will launch both Explorer and Write from the command line
Explorer&Write
You can even add a limited amount of conditional execution to your command stack using two other command separators. If you separate two command using a double ampersand (&&), then the second command will be executed only if the first command runs successfully. Running successfully means it must be a valid command, it must run to normal termination, and it must not set a nonzero errorlevel on exit. If you use a double bar (||) as command separator, then the second command will only be executed if the first command fails.