The 12V rails on a power supply are marked by a yellow wire. 12V (DC) has developed over the years into the most important supply voltage within a computer and delivers power primarily to the graphic card(s), processor and (optical) drives.
24/7 refers to hours of operation. It means that a computer (or other electronic device) can be operated 24 hours a day, 7 days a week without interruption.
20/24 pin (ATX connector)
The 20/24 pin connector – also known as the ATX plug – is the biggest and also the most important plug for a power supply unit. It is connected to the mainboard and delivers not only the three primary power voltages (3.3V, 5V and 12V) but also the power-good signal required for operation as well as 5V stand-by and -12V. The 20/24 pin connector is thus a computer's primary power supply connection.
4-pole fan motor
The most common motors in case fans have four poles. This means four windings drive the fan and let’s it operate quietly.
4+4 pin (connector)
The 4+4 pin plug is also known as the 8-pin EPS connector. It contains eight cables, including four connected to the 12V rail. The other four cables connect the power supply to the earth. This plug delivers power to modern multi-core processors. The 4+4 pin is also informally known as the 8 pin connector or p8 plug.
The 4-pin Molex plug is primarily used to connect (optical) drives and hard drives, although it is being increasingly displaced by the S-ATA connector. The Molex, as it is known informally, has four cables. These comprise two earth wires (black) and one cable each for the 5V (red) and 12V (yellow) voltage.
6-pole fan motor
The six poles of the motor produce a smoother transition between the magnetic poles. This results in very low vibration and silent operation with less energy consumption.
80 Plus Standard / bronze / silver / gold
80 PLUS is a certification awarded for a power supply's efficiency level. The more efficient the power supply, the better the level of 80 Plus certificate. The efficiency levels are differentiated using the Olympic medal system, with bronze, silver and gold certificates. More information about 80 PLUS can be found on its homepage at: http://www.80plus.org