Power Button This button allows you to turn your computer on and off. On a desktop, it is located on the front, but on an all-in-one it is on the back of the screen.
Audio Ports and USBs You can plug your phone, headphone, and flash drive in to it. You can find these ports on the front and back of your desktop. You will usually have many USB ports.
Power Socket & Ethernet Port The power socket is located on the back of your desktop. It allows you to plug your computer and have power. The Ethernet port allows you to connect to the internet.
Parallel & Serial Port This port is use to connect other things such as a printer. Today, most printers have a USB port, so you may not need to use them.