The document defines and describes various computer components and ports. It explains what the monitor system unit, CD ROM/DVD drive, floppy disk drive, USB port, headset/speaker jack, microphone jack, power outlet, exhausted fan, expansion slot, LAN port, VGA port, LINE IN/OUT, PS/2 mouse and keyboard slot, parallel port, and serial port are. It also provides details on CD ROM, DVD drive, USB port, floppy disk, PCI slot, VGA port, DVI port, PS/2 port, parallel port, and serial port. Lastly, it compares PS/2 vs USB and CD ROM vs DVD ROM.