Final answer:
A jumper is a set of two small posts or pins on a motherboard or other computer component used to close or open a circuit to configure settings, such as the status of a hard drive or to reset CMOS.
Step-by-step explanation:
The term that defines two small posts or metal pins on the motherboard that are either open or closed is known as a jumper. Jumpers are used on motherboards and other computer components to configure settings, such as the operation mode of the hard drive or motherboard, or to reset the CMOS settings. Jumper caps can be placed on the pins to either short them (closed) or left off for an open state, depending on desired settings.
To configure a jumper, you typically use a small plastic cap to bridge two pins together which changes the electrical circuit and alters the configuration settings of the device. A common example where jumpers are utilized is to set a hard drive as a master or slave in the IDE configuration. Also, clearing CMOS by changing the jumper position to reset the BIOS is a familiar application to many technicians. These small components play a crucial role in system setup and configuration.