A trace route is a special program that will monitor the network path of test data transmitted to a distant network. A trace route program is already there in the shell of Linux and unix, whereas on windows it is the equivalent of the trecert program which can be accessed through the DOS prompt.
These programs take up the name or an IP address of a distant remote computer, through the command line. They are used to send a multitude of test messages through the network and via intermediate routers until the message arrives at its destination.
At the end of the process the trace route program will generate a list of routers that were used to pass the message to its final destination.