POWER SUPPLY:

 Do not confuse a power supply with a power source. The source is the origin of incoming electricity. The electricity source is usually an outlet, battery, or generator. The power supply converts the power from the source into the correct format and voltage. Because various options exist, the specific power supply function depends on whether it needs to regulate energy or convert power. To understand a power supply and its workings, you must know its parts and their contributions to the device’s operation, as discussed below.