A Motherboard, also known as a mainboard, main circuit board, MB, mboard, base board, system board, or logic board in Apple computers, is a circuit board that connects hardware components to a computer is the primary printed circuit board (PCB) of expandable systems, such as general-purpose computers. It provides connectors for various peripherals and keeps and enables communication between many of the important electronic parts of a system, including the memory and central processor unit (CPU). In contrast to a backplane, a motherboard frequently houses important sub-systems such the central CPU, input/output and memory controllers for the chipset, interface connectors, and other parts that are integrated for general usage. 

references: https://en.wikipedia.org/wiki/Motherboard

A Power supply is a unit of electrical equipment that powers electrical loads. A power supply's primary function is to transform electrical current from a source into the proper voltage, current, and frequency needed to drive a load. Because of this, power supplies are sometimes known as electric power converters. While some power supplies are integrated into the load appliances they power, others are independent standalone pieces of equipment. All power supplies have one or more power output or rail connections that send current to the load and at least one power input connection that accepts energy in the form of electric current from a source. 

references: https://en.wikipedia.org/wiki/Power_supply

A data cable and a power cable are the two basic categories of computer cables. A data cable is a cable that allows devices to communicate with one another. For instance, the DVI, HDMI, or VGA data cable that connects your computer to your monitor enables it to show a picture on the monitor. The CAT5, IDE/EIDE, SATA, and USB cables are other common types of data cables. Any cable that powers the gadget is a power cable. Power cables include, for instance, the cord that powers your computer and a Molex-style cable found within the device. 

references: https://www.computerhope.com/jargon/c/cable.htm