Peripheral Types | CompTIA A+ 220-1001 | 3.6

In this video you will learn about various peripherals and their uses.

Computer Peripheral

By definition, a computer peripheral is any external device that provides input and output for the computer. Some are designed to input data, and others are designed to output data from the computer.


A printer is a peripheral device which makes a persistent representation of graphics and/or text, usually on paper.  Printer, including multifunction devices (print/scan/copy or print/scan/copy/fax) require specific drivers to be installed before the device is connected to enable full use of device features.  Some operating systems like Microsoft Windows or Apple’s macOS systems may have drivers to popular printers already preinstalled, but you may come across cases where the printer is outdated and the drivers to operate them may need to be manually installed in order for the printer to fully function. Standalone or networked printers enable the printing of paper documents from applications.  Laser printers are common in business, and inkjet printers are common for home use.

ADF & Flatbed Scanners

In multifunction or all-in-one printers, fax machines, photocopiers and scanners, an automatic document feeder (ADF) is a feature which takes several pages and feeds the paper one page at a time into a scanner or copier, allowing the user to scan, and thereby copy, print, or fax multiple-page documents without having to manually replace each page.

Automatic Document Feeder (ADF)

An image scanner is a device that optically scans images, printed text, handwriting or an object and converts it to a digital image. All scanners can connect via a USB port; some can also use WiFi.  Almost every multifunction device includes a flatbed scanner with resolution up to 2,400dpi.  Most of these also include a sheet folder for easier scanning of multiple pages. Scanners made for photos typically support resolution up to 4,800dpi or greater. A driver is typically installed before the scanner is connected.  Drivers are available for Windows and macOS, and portable models also support Android and iOS.  Some scanner vendors also provide Linux drivers.

Typical Scanner

Barcode & QR Scanners

A barcode reader is an optical scanner that can read printed barcodes, decode the data contained in the barcode and send the data to a computer. Like a flatbed scanner, it consists of a light source, a lens and a light sensor translating for optical impulses into electrical signals. Additionally, nearly all barcode readers contain decoder circuitry that can analyze the barcode’s image data provided by the sensor and sending the barcode’s content to the scanner’s output port.

Types of barcode readers:

  • Pen-based: readers use a pen-shaped device that includes a light source and photo diode in the tip.
  • Laser scanners: used in grocery and big-box stores.
  • CCD or CMOS readers: use a hand-held gun-shaped device to hold an array of light sensors mounted in a row.
  • Camera-based readers: contain many rows of CCD sensors that generate an image of the sensor that is processed to decode the barcode information.
Barcode Reader

A QR code (Quick Response code) is a two-dimensional machine-readable optical label that contains information about the item to which it is attached which can be read by a scanner or a mobile phone. QR codes often contain data for a locator, identifier, or tracker that points to a website or application. QR codes use four standardized encoding modes (numeric, alphanumeric, byte/binary, and kanji) to store data efficiently; extensions may also be used.

QR Code


A computer monitor is an output device that displays information in pictorial form. A monitor usually comprises the visual display, circuitry, casing, and power supply. The display device in modern monitors is typically a thin film transistor liquid crystal display (TFT-LCD) with LED backlighting. Monitors are connected to the computer via VGA, DVI, HDMI, DisplayPort, Thunderbolt, low-voltage differential signaling (LVDS) or other proprietary connectors and signals. Some monitors use touchscreen technology that enables both input and output from the monitor.

VR Headset

A virtual reality (VR) headset is a head-mounted device that provides virtual reality for the wearer.  Virtual reality is computer simulations projected into a headset that covers the user’s entire field of vision, creating a virtual world experience. Inside the mask, two LED panels (one for each eye) are located inside the head mounted device (HMD).  The visual feed to these panels is adjusted to create the 3D effect. The HMD can monitor head movements, and a special glove can add hand inputs, so the user can move around in the 3D environment.

VR Headset

Optical Drive Types

In computing, an optical drive is a disc drive that uses laser light or electromagnetic waves within or near the visible light spectrum as part of the process of reading or writing data to or from optical discs by way of continuous spirals of indentations called pits and lands that are burned into the non-label side of the disc from the middle outward to the edge. There are 3 main categories for optical drives CDs, DVDs, & Blu-ray. Due to most modern laptops being shipped without optical drives, external optical drives are a good solution for when the use of an optical drive is necessary. They connect via USB and usually self-load drivers.

External Optical Drive


A computer mouse is a handheld hardware input device that can be wired or wireless that controls a cursor in the GUI (graphical user interface) and can move and select text, icons, files, and folders on your computer.  A standard mouse is a plug-and-play device as well. Windows, macOS, and Linux include mouse drivers.  To install a USB mouse, simply plug it in, and the operating system installs the drivers needed. Mouse alternatives, such as touchscreens, trackballs, and touchpads, are considered mouse devices because they install and are configured the same way. If a mouse uses Bluetooth, it needs to be paired with the computer’s Bluetooth receiver.


A keyboard is one of the primary input devices used with a computer.  Similar to an electric typewriter, a keyboard is composed of buttons that create letters, numbers, and symbols, as well as perform other functions.  A standard keyboard, unlike a printer, scanner or other multifunction device, is a plug-and-play device meaning, it is automatically recognized by the operating system.


A touchpad (also known as a trackpad) is a pointing device featuring a tactile sensor, a specialized surface that can translate the motion and position of a user’s fingers to a relative position on the operating system that is made output to the screen. Touchpads are a common feature of laptop computers as opposed to using a mouse on a desktop, and are also used as a substitute for a mouse where desk space is scarce. Touchpads can also be externally connecting devices which can connect via USB and self-install drivers as well.

External Touchpad

Signature Pad

A signature pad is a device that electronically captures a person’s handwritten signature on an LCD touchpad using a pen-type stylus. As a user digitally “signs” a data capture’s LCD touchpad, a sensor “reads” the pressure from the tip of the stylus, transmitting signature data to a computer. Signature pads are used in banking, medical, retail, and other environments where signature verification is required. Most signature pads use a USB interface.

Signature Pad

Game Controllers

A game controller is usually a handheld input device used with video games or entertainment systems to provide input to a video game, typically to control an object or character in the game. Game controllers, game pads and joysticks typically plug into a computer’s USB port, although there are plenty that utilize wireless connections as well.


Two types of camera can be added to a desktop or a laptop:

  • A webcam, which is a camera that connects to a computer.  It captures either still pictures or motion video, and with the aid of software, can transmit its video on the internet in real-time.
  • A digital camera, which can use the desktop or laptop as a permanent storage location for the photos or videos you have already taken.

Both types of camera connect to a USB port.

Typical External Webcam
Digital Camera


A microphone is a device that converts sound into an electrical signal. A microphone can connect to a computer via the 3.5mm mini-jack microphone jack (or to a USB port) which is directly connected to a sound card mounted on the motherboard.

Computer Microphone


Computer speakers can be connected in one of several ways to a PC, depending on the computer:

  • 3.5 mm (mini-jack)
  • HDMI
  • S/PDIF
  • USB
  • Proprietary sound card header cable

Most desktop computers use integrated sound, but some use a sound card for higher-quality sound.


A headset combines a headphone with a microphone. Headsets are made with either a single-earpiece (mono) or a double-earpiece (mono to both ears or stereo) and connects to a computer either wirelessly or with a USB connection. Headsets provide the equivalent functionality of a telephone handset but with handsfree operation.


A projector is an optical device that projects an image (or moving images) onto a surface, commonly a projection screen. Most projectors create an image by shining a light through a small transparent lens, but some newer types of projectors can project the image directly, by using lasers. Projectors can support USB, DVI-D, HDMI, and DisplayPort connections.


Brightness is an attribute of visual perception in which a source appears to be radiating or reflecting light. In other words, brightness is the perception elicited by the luminance of a visual target. The brightness of an LCD display is measured in candelas per square meter (cd/m^2), sometimes referred to as “nits”.  The higher this value, the brighter the display.

Lumens (lm) are a measure of the total amount of visible light (to the human eye) from a light source. The higher the lumen rating, the “brighter” the light source will appear. The brightness of a projector is measured in lumens.

External Storage Drives

In computing, external storage comprises devices that store information outside a computer. Such devices may be permanently attached to the computer, may be removable or may use removable media. External storage is commonly in the form of a USB thumb drive or an eSATA hard drive.


A keyboard-video-mouse switch is a hardware device that allows a user to control multiple computers from one or more sets of keyboards, video monitors, and mice. Some servers are controlled directly from a display, keyboard, and mouse the same way the desktops are, but many are controlled using a KVM switch (keyboard, video, mouse) or with remote access software.

Typical KVM Switch

Magnetic Reader/Chip Reader

A card reader is a data input device that reads data from a card-shaped storage medium. Modern card readers are electronic devices that can read plastic cards embedded with either a barcode, magnetic strip, computer chip or another storage medium. Common uses for magnetic & chip readers is for payment services.

Chip Reader

NFC/Tap Pay Device

Near-field communication is a set of communication protocols that enable 2 electronic devices, one of which is usually a portable device such as a smartphone, to establish communication by bringing them within 4 cm of each other.  NFC enables smartphones to be used for payment services such as Apple Pay, Samsung Pay, and others. NFC also enables file transfer between supported devices. To transfer files between smartphones with NFC, both smartphones must have NFC enabled and an NFC file transfer utility enabled, such as S Beam (Samsung smartphones) or Android Beam (Android smartphones).  Once that is enabled, simply tap the phones together to transfer files. NFC can also be used with compatible printers for tap-to-print capabilities.

Smart Card Reader

A smart card is a physical electronic authorization device, used to control access to a resource. It is typically a plastic credit card-sized card with an embedded integrated circuit chip. External smart card readers connect via USB ports.  Once a smart card reader has been installed, it works the same as a built-in smart card reader for controlling access or restricting resources. Smart card readers are supported by Windows, macOS, and popular Linux distributions.  A driver is typically installed automatically when a smart card reader is connected.