CompTIA A+® Certification All-In-One For Dummies®, 2nd Edition

1.1. Identifying Common Computer Ports

Start by looking at the different types of ports on the back of your computer. Ports are connection points on your computer that allow for devices to be connected to your computer. The connection point has a connector that accepts a cable with a matching connector. Knowing what the ports are used for is important when connecting devices to your computer. You might already be familiar with some of the common ports, such as serial, parallel, and USB. In this section, I discuss these ports as well as IEEE 1394 ports, which are often called FireWire.

1.1.1. Serial and parallel ports

Two of the most common computer ports are serial ports and parallel ports. Most computers have one parallel port and two serial ports. These ports are used to connect devices, such as modems and printers, to your computer.

NOTE

There has been a trend in the industry to create legacy-free computers: that is, computers without COM ports, LPT ports, or ISA expansion slots, as well as number of other functional changes. Many new laptops on the market already fit into this category.

Parallel ports send data over multiple wires simultaneously; serial ports send data over only one wire at a time. Because parallel communication allows for multiple streams of data, which in the early days, when serial controllers were slow, allowed it to provide higher data transfer rates than serial communication. This is no longer true today.

Parallel ports were implemented on the personal ...