Optical Disc Drive Often called a CD-ROM or DVD-ROM drive, this lets your computer read CDs and DVDs.
Power Button The power button is used to power the computer on and off.
Audio In/Audio Out Many computers include audio ports on the front of the computer case that allow you to easily connect speakers, microphones, and headsets without fumbling with the back of the computer.
USB (Universal Serial Bus) Port Most desktop computers have several USB ports. These can be used to connect almost any type of device, including mice, keyboards, printers, and digital cameras. They will often appear on the front and back of the computer.