# Lesson Notes — Peripherals, Ports, & Connections

- Link: https://doss.academy/course-1-computer-literacy/unit-2-pc-hardware-system-architecture/lesson-2-peripherals-ports-connections/lesson-notes-c1u2l2/
- Published: 2026-10-19T12:09:07-04:00
- Author: matthew.leffler@jefferson.kyschools.us

Course 1: Computer Literacy / Unit 2: PC Hardware & System Architecture / Lesson
2: Peripherals, Ports, & Connections

## Lesson overview

A computer on its own cannot do much. It needs devices to put information in, devices
to show results, and cables or wireless links to tie everything together. This lesson
helps you match the right device to the right port.

## Peripherals

A **peripheral** is a device you connect to a computer. An **input device** sends
information in, such as a keyboard, mouse, scanner, or microphone. An **output device**
sends information out, such as a monitor, speakers, or printer.

## Common ports and connections

  |  Connection |  What it is used for |  
   |  **USB** |  Keyboards, mice, flash drives, phones, and many other devices. USB-C is a small, reversible connector that works either way up. |  
 |  **HDMI** |  Sends both video and sound to a monitor or TV. |  
 |  **DisplayPort** |  Sends video, and sound, to computer monitors. Common on PC graphics cards. |  
 |  **Ethernet** |  A wired connection to a network, often steadier than Wi-Fi. |  
 |  **Bluetooth** |  A short-range wireless link for headphones, keyboards, and speakers. |

## Adapters and expansion

 * A **dongle** is a small adapter or receiver that plugs into a port. For example,
   a wireless mouse may use a tiny USB receiver, and a USB-C to HDMI adapter lets
   a thin laptop use a monitor.
 * An **expansion slot** is a socket on the motherboard where you can add a card,
   such as a graphics card, to give the computer new abilities.

## When a device does not work

Use the troubleshooting steps from Unit 1. Is the cable fully pushed in? Are you
using the right port? Does the device need to be turned on or paired? Try restarting
the device, then the computer.

## Check your understanding

 1. Is a printer an input device or an output device? What about a touchscreen?
 2. You want to connect a laptop to a TV for a presentation. Which connection might
    you use?
 3. Your Bluetooth headphones will not play sound. List two things you would check.

Use this lesson’s Key Terms page to build your glossary.