Understanding Ports

Everything that's hooked up to your PC is connected via some type of port. A port is simply an interface between your PC and another device either internally (inside your PC's system unit) or externally (via a connector on the back of the system unit).

Internal ports are automatically assigned when you plug a new card in to its slot inside the system unit. As for external ports, many types are available each optimized to send and receive specific types of data. Different types of hardware connect via different types of ports.

The most common types of external ports are shown in Table 7.1.

Table 7.1. External Ports

Connector	Type	Uses	Description
	Serial	Modems, printers, mice	Enables communication one bit at a time, in one direction at a time.
	Parallel	Printers, scanners	Enables communications going in two directions at once.
	USB	Almost anything portable devices, printers, scanners, modems, external sound cards, mice, keyboards, joysticks, CD/DVD drives, hard drives, digital cameras	A newer, faster, more intelligent type of serial port. USB devices can be added while your computer is still running, which you can't do with older types of ports.
	FireWire	Digital cameras, digital camcorders, hard drives, CD/DVD burners	Also called IEEE 1394, this is a newer interface standard that enables hot-pluggable, high-speed data transmission.
	SCSI	Hard drives, CD/DVD drives, tape backups	The small computer system interface (SCSI) port is a high-speed parallel interface.
	Gameport	Joysticks and other game controllers, MIDI devices	This port is typically used to connect gaming controllers; also functions as a MIDI port with the appropriate adapter.
	Keyboard/Mouse	Keyboards, mice, other input devices	Sometimes called a PS/2 port, used to connect both wired and wireless input devices.