There are computer board jumpers, fiber optic jumpers, network jumpers, etc.
From the appearance, the "jumper" of the computer's internal board card is a small metal rod (jumper post) embedded in devices such as the motherboard, sound card, and hard drive, as well as a small clip (jumper clip) placed on these metal rods. The function of jumpers is to adjust the on/off relationship of different electrical signals on the device and adjust the working status of the device, such as determining the motherboard voltage, the master-slave relationship of the driver, and so on. When the jumper clamp is connected to two jumper posts at the same time, it indicates that these two jumper posts are connected. If only one or no jumper post is connected, it indicates that it is disconnected. Adjusting the jumper is very important. If you make a mistake, it can cause a crash or even burn the entire device. Therefore, when adjusting the jumper, it is necessary to carefully read the manual, verify the jumper name, jumper column number, and connection/disconnection relationship.
The jumpers on the motherboard generally include CPU setting jumpers, CMOS clearing jumpers, BIOS prohibiting writing jumpers, and so on. Among them, setting jumpers on the CPU is the most complex. If the motherboard is relatively old, it is necessary to set kernel voltage, external frequency, and octave jumpers on the motherboard. According to the motherboard manual and CPU frequency, set the corresponding jumpers mentioned above. Usually, a set of jumpers corresponds to the CPU voltage on the motherboard, and each jumper corresponds to a voltage value. Find the appropriate voltage value, insert a keycap to short it, and select this voltage value. Similarly, find the external frequency jumper and octave jumper, and set the appropriate external frequency and octave respectively. Note that only one jumper can be selected for short circuiting in each group of jumpers.
The jumper here refers to a copper connecting wire, made of standard jumper cables and connecting hardware. The jumper cable has copper cores ranging from two to eight cores, and the connecting hardware is two 6-bit or 8-bit module plugs, or they have one or more bare wire ends. Some jumpers have a module plug at one end and an 8-bit module slot at the other end, or are equipped with 100P wiring plugs, MICs, or module slots. Jumpers are used to connect various links on the distribution frame and can be used as cables for connecting the distribution frame or equipment. Both ends of the modular jumper are RJ45 connectors, using TIA/EIA-568A pin structure, and have a flexible plug and drop design to prevent loosening and jamming. Jumpers can range in length from 1 foot (0.305 meters) to 500 feet (15.25 meters), with the most commonly used lengths being 3 feet, 5 feet, 7 feet, and 10 feet. Modular jumpers are used in the work area and can also serve as jumpers between wiring. In the installation of DIY in small office or home networks, it is often mentioned that dual computer interconnection jumpers are used. This type of jumper is not a standard jumper used in comprehensive cabling, but a special hardware device connection cable. It is used when connecting two PC computers directly with twisted pair cables or when two HUBs need to be connected through the RJ45 port, a crossover (commonly known as a crossover or jumper) is required. It follows a specialized connection sequence.