Network Switch

A network switch or switching hub is a computer networking device that connects network segments.

The term commonly refers to a network bridge that processes and routes data at the data link layer (layer 2) of the OSI model. Switches that additionally process data at the network layer (layer 3 and above) are often referred to as Layer 3 switches or multilayer switches.
Click this link to view video : http://www.youtube.com/watch?v=V2JVitiy4tQ

Router

A router is an electronic device that interconnects two or more computer networks, and selectively interchanges packets of data between them.
Further info, please click :
http://communication.howstuffworks.com/convergence/router.htm

Cable Tester

     

A cable tester is an electronic device used to verify the electrical connections in a cable or other wired assembly.

 

Computer Upgrade & Assembly

Desktop PC Back Panel

                     Desktop Back Panel