Final answer:
A converter, often referred to as a rectifier, is the device that changes AC to DC. It uses diodes to ensure one-way current flow, producing a steady DC output for devices requiring DC power.
Step-by-step explanation:
The device used to change alternating current (AC) to direct current (DC) is known as a converter. This device is also sometimes referred to as a rectifier. Converters are commonly used to supply DC power to devices such as computers and cell phones. While solar cells produce DC, most home appliances require AC, leading to the use of an inverter to change DC back to AC. Conversely, for devices that operate on DC, it is a converter that takes AC from the wall socket and converts it into DC voltage that the devices can use. This is accomplished through the use of diodes within the rectifier which only allow current to flow in one direction, thereby producing a steady DC output.