What A Router Is

Bacically, a router allows you to set up more than one computer to share internet access at the same time, primarily for small networks like those used in homes and small offices.

Routers are mainly used where the Internet connection is an Always-on broadband connection like cable modem or DSL.

A router is "technically" defined as a device that selects the best path for a data packet to be sent from one computer network to another. A router is located at any gateway (where one network meets another), and is often included as part of a network switch.

A network switch is a small device that joins multiple computers together at a low-level network protocol layer. Network switches are capable of inspecting the data packets as they are received, determining the source and destination device of that packet, and forwarding that packet appropriately.
 
Most devices, although contain and/or operate as a network switch, fall under the more common term "Router".  These are not "routers" in the true sense, but the terminology has been interchanged with Network Address Translation (NAT).  When you set up the configuration of your router, you may see the term NAT used.  NAT is simply the technical term used for the process of determining the destination of data packets.  

The electronic messages sent between computer networks are stored in the router, while it determines all of the possible paths to the destination address. The router then chooses the most expedient route, based on its investigations, before forwarding the data to the final destination (the computer requesting  that information).  
For example when you request a webpage, this information is sent to the correct computer on your network.

Some porgrams will require you to configure your router to allow the data on certain ports, so that it can determine the best route, for example WinMX.  You can access your router through your internet browser, for more information on how to do this see Understanding Port Forwarding.

Some routers contain firewalls, so please be sure to check your brand and model, this will help you when you are ready to set up your configurations.

A Simple Diagram of a Basic Home Network set-up.




Please note :  For your router to work properly with WinMX, you will need to configure your ports.  
Be sure to read our section on Understanding Port Forwarding to learn more about how this is done.  Hopefully this helps you to understand the basic function of a router.