56 kilobytes per second is the standard. Expansion slots refer to the areas in which you can add peripheral devices or special add-ons. Most computer systems have a minimum of 5 expansion slots available. Expansion slots are inside the computer connected to the motherboard. Expansion Cards, like a modem are connected to the slots.
Ports come in two kinds, both of which are standard items.
The serial port is the one to which you'll attach your keyboard and mouse. The parallel port is the one to which you attach your printer or other high data peripheral devices such as scanners. DVD stands for digital video disc players. This newest technology was introduced to the market in March 1997. The device is intended to eventually replace the CD player although, in my opinion.