Parallel Port

A parallel port is a 25-pin female port, which is most commonly used to connect printers or scanners to the computer.

Other devices that can be connected to the parallel port include external Zip drives, external hard drives and external CD-ROM drives.

It is also possible to network computers together via their parallel ports.

Serial or Com Ports

Serial ports traditionally came in two sizes: a 25-pin male port and a 9-pin port. Most computers these days are provided with 9-pin serial ports, as pictured here.

A mouse and a modem are the two most common devices that are attached through serial ports. In the past, printers were also connected via the serial port. Computers can be networked via their serial ports and digital cameras can also interface through serial ports.

Serial ports are generally very slow compared to other ports, such as parallel and USB.

Universal Serial Bus (USB)

The Universal Serial Bus, or USB, is a newer version of a serial communications port for communication between the computer's Central Processing Unit and hardware devices.

The USB is gaining in popularity for connecting peripherals as it is Plug and Play (plug it in and the operating system will recognise it right away), it is powered through the motherboard so no power connections are needed, and the devices can be "piggy-backed" to one another so only one port is needed to connect a number of devices.

Scanners, printers, and digital cameras are now commonly connected to the computer via the USB interface.

Keyboard Connection

Keyboard connection to the motherboard of the computer can be either via a 5-pin DIN port or a PS/2 port (pictured here). The DIN port was the most common keyboard connection in the past, but the PS/2 connector is now much more common.

Note: DIN stand for Deutsche Industrie Norm; translated, this means German Industry Standard. Like the 25-pin serial port, it may have been an existing electrical interface that was adapted for use in computers.

SVGA or Video Port

SVGA stands for Super Video Graphics Array and it is the present standard interface for connecting a monitor to the system.

The SVGA port on the video card is female and has 15 points of connection.

Sound Cards

Sound cards may have a variety of ports available – depending on the model. Generally however, you will find a speaker out connector (for small speakers), a line out connector (for amplified speakers), a microphone in connector (for microphones), and an audio in connector (for other audio devices).

Internal Modem

The picture here displays a connection for an internal modem. This is where the phone line is connected.

This connection is referred to as an RJ-11 connector.

Some internal modems may have two of these connections – one for voice, and one for data.

Network Cards

Computers in businesses and educational institutions are nearly always on a network. Each computer would have a network card inserted into one of its slots on the motherboard.

There are two popular types of cable for connecting networked computers: coaxial cable and twisted pair cable.

Game Port

Most machines will have a game port connector – used for connecting game playing devices, such as a joystick.

Power Connector

Every machine has a power connector of some sort – pictured here is the standard 240 volt connector.