1. A piece of a physical circuitry component that governs signal flow. Having a switch or toggle switch allows a connection to be opened or closed. When opened the switch allows a signal or power to flow through the connection. When closed the switch stops the flow and breaks the circuit connection.
2. On a network, a switch is a hardware device that filters and forwards packets through the network, but often not capable of much more. The first network device that was added to the Internet was a switch called the IMP, which helped send the first message on October 29, 1969. A network switch is more advanced than a hub but not as advanced as a router. In the picture to the right, is an example of a SMC EZ Switch, a 10/100 network switch.
3. A button or lever that can be switched to turn a device on or off.
4. When referring to the switches command, this command is loaded through config.sys and allows you to add and remove various functions of MS-DOS. See the switches command for further information about this command.
5. When referring to another command, a switch is an available option that can be used with the command. For example, the command: "fdisk" can be used with the /MBR switch, using "FDISK /MBR" would allow the user to recreate the master boot record and not just run the fdisk program.