The power supply as its name might suggest is the device that supplies power to all the components in the computer. Its case holds a transformer, voltage control, and (usually) a cooling fan. The power supply converts about 100-120 volts of AC power to low-voltage DC power for the internal components to use. The most common computer power supplies are built to conform with the ATX form factor. This enables different power supplies to be interchangable with different components inside the computer. ATX power supplies also are designed to turn on and off using a signal from the motherboard, and provide support for modern functions such as standby mode.
That said, your Build already looks solid, upgrade options might be a 970 evo for the 860 evo, and also be sure to get a 32gb ram kit and not 2 16gb ones. The kits that are packaged together are also tested together and will run without problems. Also Ryzen CPUs like faster RAM so if you have the money think about 3200mhz RAM. For example: https://amzn.to/2Gy9UWB
A storage device is any computing hardware and digital media that is used for storing, porting and extracting data files and objects. It can hold and store information both temporarily and permanently, and can be internal or external to a computer, server or any similar computing device. Data storage is a core function and fundamental component of computers.
The hardware components described so far result in a fully functional computer system. A user can provide input using the keyboard and the mouse, and the computer can process instructions, read and write information, and display the results on the monitor. Most present-day computer systems have additional hardware components to provide more functionality. These include input devices, such as a microphone and video camera, and output devices, such as speakers. These can be integrated into the other hardware components or connected as external devices.