Output Devices and Their Role

This lesson covers output devices — what they are, how they work, and how to choose the right output device for a given scenario. This is part of OCR J277 Section 1.1.1.

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What Is an Output Device?

An output device is any hardware component that presents processed data from a computer to the user or to another system. Output devices convert digital data from the computer into a form that humans can understand (such as images on a screen, sound from speakers, or text on paper).

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Common Output Devices

Monitor / Screen

Feature	Detail
How it works	Displays images by lighting up individual pixels in combinations of red, green, and blue (RGB)
Types	LCD, LED, OLED, IPS
Use	Displaying the operating system, applications, video, and images
Key specifications	Resolution (e.g. 1920x1080), refresh rate (e.g. 60 Hz), screen size

Resolution refers to the number of pixels on the screen. A higher resolution means a sharper, more detailed image:

Resolution	Name	Pixels
1920 x 1080	Full HD (1080p)	~2.07 million
2560 x 1440	QHD (1440p)	~3.69 million
3840 x 2160	4K UHD	~8.29 million

Printer

There are two main types of printer:

Inkjet Printer:

Feature	Detail
How it works	Sprays tiny droplets of liquid ink onto paper
Strengths	High-quality colour printing, good for photos
Weaknesses	Slower, ink cartridges can be expensive, ink can smudge

Laser Printer:

Feature	Detail
How it works	Uses a laser to create a pattern on a drum, which attracts toner (powdered ink) and transfers it to paper using heat
Strengths	Very fast, low cost per page, excellent text quality
Weaknesses	More expensive to buy, colour laser printers are costly

Comparison	Inkjet	Laser
Speed	Slower	Faster
Cost per page	Higher	Lower
Photo quality	Excellent	Good
Text quality	Good	Excellent
Initial cost	Lower	Higher

Speakers / Headphones

Feature	Detail
How it works	A DAC (digital-to-analogue converter) converts digital audio data into electrical signals, which drive a speaker cone or headphone driver to produce sound waves
Use	Music, video audio, voice calls, alerts, accessibility

Projector