Commonly referred to as internal Molex connectors on a desktop computer. It is used for peripherals that require more amperage than that provided by the data cable such as:

• Hard drives (IDE, SCSI and SATA)
• Units diskettes (3.5 'and 5.25 ")
• Optical drives (CD, DVD and Blu-Ray)
• Video cards (PCI-e plates, PCI and AGP)
• Cooling systems (air and liquid)
• Modding circuits (LEDs, light pipes, etc.)
• Naturally, there are two types of Molex connectors, a male connector and a female connector. Plugs are used to branch outlets and split them into two but most of the time are integrated into the PCB peripherals.

The electrical conductors exiting the power supply toward Molex connectors have colorsdistinguish:

Within the different types of electrical cables we can find single or multifilament cables. The difference lies in the number of conductors that make up the cable. Single wire cables contain only a single conductive wire, whereas multi-wire cables contain more than one wire. Do not confuse multifile (A) or single wire (B) with monopolar (C), bipolar (D) or multipolar (E) cable. Monopolar cables have only oneSingle conductor, bipolar cables have two conductors, while multi-pole cables have more than two conductors. It may be said that any unipolar, bipolar or multipolar cable can be single-ended or multi-stranded. In the case of single wire cables we will talk about rigid cables, whereas the multifilament cables will be flexible.
In the following table you can see the difference between them.