According to wikipedia, traceroute is a computer network tool used to determine the route taken by packets across an IP network. An IPv6 variant, traceroute6, is also widely available. Mainly use to trace how a data packet goes from one location to another location.
Example : A worker inside a company accessing a web site through his browser. First, data packet will transfer from his PC’s network adapter to his company Internet Router, and from Internet Router to the web page web server. At the middle of it, the particular data packet may pass through several servers/ switches / routers at the middle of the ‘road’. A simple concept is like where we trace how to drive from a location to the other location. It might have shortest or longest way to reach the destination, or passing through extra traffic lights and junctions.
You can try to trace a locations, in order to check how data packet transfer within 2 points.
Windows XP
1. Start > run > type cmd
2. type tracert , eg: tracert http://www.yahoo.com
Unix/Linux Bash
1. Execute linux bash console
2. type traceroute , eg: traceroute http://www.google.com
References
General Knowledge : http://en.wikipedia.org/wiki/Traceroute
TraceRoute Knowlege : http://www.traceroute.org
Tracert for Expert :http://www.windowsnetworking.com/articles_tutorials/Using-Tracert.html
Ah Khai Tech 