Power Supply              

• All of the components of a computer system require power of electricity to function. 
  
• The unit that provides the power to the system known as the power supply unit. 
  
• The additional cables those are required   
  to connect the power supply to the wall power outlet is called power cables  
  to connect the devices to the power supply is called power connectors

The main power is connected to the power supply through a power cable. The power required by the devices is supplied through the power connectors of the power supply.

The power connectors come in different shapes and sizes. They also supply different voltages. To avoid the incorrect connection of the power connectors to the devices they usually have special shapes or keys.

• Mini plug - provides power to the floppy drive, 4 pins
• Molex power connector - provides power to hard drives, CD/DVD drives and SCSI (Small Computer System Interface) drives
•Motherboard power connector - These can defer according to the form factor of the motherboard, but their primary task is to provide power to the mother board. 20 pins
• 12V ATX power connector - this is required to provide additional power to the Pentium 4 processor. This is plugged into the motherboard, 4 pins (12v)
• SATA (Serial Advanced Technology Attachment) power connector - provides power to the SATA hard drive, 15 pins