Without those ports at the back, you would have no where to plug your monitor, your mouse, your keyboard, your printer, your scanner etc...
input/output ports
The front panel of a system unit typically includes power button, reset button, USB ports, headphone and microphone jacks, and sometimes indicator lights for power and storage activity.
The system unit, often referred to as the computer case or chassis, is typically a rectangular box that houses the internal components of a computer. It features a front panel with ports for USB and audio connections, while the back panel includes ports for connecting peripherals like monitors and keyboards. Inside, it contains essential components such as the motherboard, CPU, RAM, storage drives, and power supply. The design can vary in size and style, from compact mini-towers to larger desktop units.
Diagram of a system unit(back view)
PS2 style plugs were used prior to USB style plugs.
A computer system unit is the case with the motherboard and all the ports. The box you unplug and walk around with. The CPU is the Central Processing Unit, this is a chip on the motherboard that does all the processing.People erroneously refer to system unit as CPU.
To change out the flasher unit on a Holden Astra you must remove the back panel of the rear unit and access the bulbs. If the bulb in the flasher is not broken then you may need to replace the flasher relay system.
System unit components include the processor, memory module, cards, ports, and connectors. Many of the system unit's components reside on a circuit board called the motherborad.
There should be an access panel under the back seat. Remove the panel, then the tank panel to remove the unit for replacement. Make sure that the battery is disconnected first.
The AC low side service ports for a 99 Oldsmobile Aurora are located on the AC unit. This unit is located between the engine block and the back firewall of the vehicle under the hood. The service port is typically the largest port on the back of the AC unit.
On the BACK SIDe of the fuse panel. Access is from the DRIVERS side kick panel
The system unit typically consists of the motherboard, CPU (Central Processing Unit), RAM (Random Access Memory), hard drive, power supply, optical drive, ports (e.g. USB, HDMI), expansion cards, cooling system (fan), BIOS (Basic Input/Output System), and front panel connectors.