Which of the following is an input device?
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Computer Literacy · Foundations
Input and Output Devices
On this page 9 sections
In 30 seconds
Input devices carry information into a computer; output devices carry results back out to you. A keyboard, mouse, microphone, and webcam are inputs. A monitor, printer, speakers, and projector are outputs. Some devices, such as a Touchscreen A display that also senses touch, so it works as both an output device and an input device. Full entry → or a headset, do both. The processor works on what inputs capture and then pushes the results to outputs, and ports and wireless links such as USB, HDMI, and Bluetooth A short-range wireless standard, operating in the 2.4 GHz band, used to connect peripherals such as headphones, keyboards, and mice without a cable. Full entry → are how everything connects.
Why this matters
Every task on a computer is a loop of input, processing, and output, so knowing which devices do which helps you set up equipment, describe a problem to tech support, and buy the right gear. When a webcam, printer, or headset will not work, the fix usually depends on which Port A physical socket on a computer through which a cable connects a peripheral. Full entry → or wireless standard it uses. Understanding peripherals also makes accessibility clearer: swapping in a different Input device Hardware that captures data or control signals from the user or environment and sends them into the computer, such as a keyboard or microphone. Full entry → or Output device Hardware that takes processed information from the computer and presents it to a person, such as a monitor, printer, or speaker. Full entry → can make a computer usable for someone who cannot rely on a standard keyboard or screen.
The college version
Input, output, and the loop between them
A computer is not useful on its own; it needs a way to receive information and a way to hand results back to a person. Input devices do the first job: they capture data and control signals from the outside world and send them into the machine. Output devices do the second: they take the information the computer has processed and present it in a form a human can read, see, or hear. Between the two sits the processor (CPU), which acts on what the input devices captured and passes the finished result to the output devices. This input, then processing, then output sequence repeats constantly. When you type a search, the keyboard is the input, the processor and software do the work, and the monitor showing results is the output. Because these devices sit around the core CPU and memory rather than inside them, they are collectively called peripherals.
Common input devices
Input devices translate a physical action or a real-world signal into data the computer can store and process. The keyboard turns keypresses into characters and commands. A mouse or trackpad reports movement and clicks so you can point at things on screen. A touchscreen senses where your finger lands. A microphone converts sound into a digital signal, which is how voice notes, calls, and dictation work. A webcam captures live video. A scanner turns a paper document or photo into an image file. A game controller reports button presses and stick movement. What all of these share is direction: information moves from you, or from the environment, into the computer. Many input devices also include specialized versions, such as barcode readers, fingerprint scanners, and graphics tablets, but they all serve the same role of getting data in.
Common output devices
Output devices run the loop in reverse, converting the computer's electronic results into something a person can perceive. The monitor or display is the most common: it renders text, images, and video as light. A printer produces a physical paper copy of a document or photo. Speakers and headphones turn digital audio back into sound you can hear. A projector throws the display onto a wall or screen so a room full of people can see it. Specialized output devices exist too, such as braille embossers that raise dots for readers who are blind, and plotters that draw large technical diagrams. The defining feature is again direction: information moves out of the computer toward the user.
Devices that do both
The input-versus-output split is a useful starting point, but several everyday devices do both jobs. A touchscreen is the clearest example: it displays output as a screen and accepts input through touch, so a single surface handles both directions. A headset combines headphones (output) with a microphone (input). A multifunction printer prints (output) and scans (input) in one unit, and it can also send a low-ink message back to the computer, which is itself a kind of input. A network interface, whether wired or wireless, both sends data out to and receives data from other computers. When you meet a new device, do not assume it belongs in only one column; ask which directions data actually flows.
Ports and connections
Peripherals connect to a computer through ports and wireless links, and knowing the common names makes setup and troubleshooting far easier. USB (Universal Serial Bus) A widely used Plug and Play wired standard for connecting peripherals and carrying both data and power. Full entry → is the general-purpose wired connector for keyboards, mice, printers, scanners, storage drives, and cameras; it is a Plug and Play A design that lets a computer recognize and configure a connected device automatically, without manual setup for each one. Full entry → standard, meaning the computer recognizes many devices automatically, and it can carry both data and power. HDMI (High-Definition Multimedia Interface) A connector standard that carries digital video and audio together over a single cable, used to link a computer to a display or projector. Full entry → carries digital video and audio together over a single cable, which is why one HDMI lead can connect a laptop to a monitor, TV, or projector. The analog audio jack (the round 3.5 mm headphone port) connects wired headphones and speakers. Bluetooth is the short-range wireless standard, working in the 2.4 GHz radio band, that links wireless keyboards, mice, headphones, and speakers without a cable. These standards are maintained by industry groups, for example the USB Implementers Forum for USB and the Bluetooth SIG for Bluetooth, which is what lets devices from different makers work together. You do not need the electrical details; you need to recognize the connector or wireless link a device uses so you can plug it into the right place or pair it correctly.
Eli explains
The same idea, in plain words
Explain it like I’m 10
Picture the computer as a person thinking in a sealed room. It needs ears and eyes to take things in, and a mouth and hands to give things back. Input devices are the ways in: a keyboard, a mouse, a microphone, a camera. Output devices are the ways out: a screen, a printer, speakers. The thinking part in the middle is the processor. A few devices, like a touchscreen, are a way in and a way out at the same time. To hook any of them up, you either plug a cable into the matching hole, called a port, or connect without a wire using Bluetooth.
Picture it like this
Think of the computer like a restaurant kitchen. Orders coming in from customers are the input, the cooks are the processor doing the work, and the finished plates carried back out are the output.
Where the picture stops working
The kitchen analogy makes input and output look like separate doors, but real devices such as a touchscreen or a headset can be both doors at once, and a computer runs the whole loop in a fraction of a second rather than at kitchen pace.
Worked example
Imagine setting up a video call for the first time. You plug a webcam and a USB microphone into the two rectangular USB ports, connect an external monitor with an HDMI cable, and pair a wireless Bluetooth headset. Now trace the data. Your voice and face are captured by the microphone and webcam (input) and travel over USB into the computer. The processor and calling software combine and compress them and send them across the internet. The other person's video arrives, gets processed, and is shown on the monitor over HDMI and heard through the Bluetooth headset (output). The headset is doing double duty: its earpieces are output, its built-in microphone is input. Every part of the call is some device moving data in, the processor working on it, and some device sending results out.
Key takeaway
Input devices bring data into the computer and output devices send results back out, with the processor linking the two; some devices do both, and peripherals attach through named ports and wireless links such as USB, HDMI, the audio jack, and Bluetooth.
Quick check
3 questions here, of 5 in this lesson’s practice set. Answers stay hidden until you check.
What best explains why a touchscreen is considered both an input and an output device?
Choose an answer, then check it.
In the input-process-output loop, what role does the CPU play?
Choose an answer, then check it.
Study tools & related lessonsYou’ll learn to · Common mistakes · Easily confused · Key vocabulary · Related
You’ll learn to
- Define input devices and output devices and explain the direction data flows in each.
- Classify common peripherals as input, output, or both.
- Explain how the CPU links the input and output stages of a task.
- Identify common ports and wireless links (USB, HDMI, audio jack, Bluetooth) used to connect peripherals.
- Distinguish a peripheral from the core processing and storage components of a computer.
Common mistakes
Assuming every device is either input or output, never both.
Some devices do both: a touchscreen displays and senses touch, a headset plays and records, and a network interface sends and receives.
Calling the monitor or printer part of the computer's 'brain'.
Those are output peripherals. The processing happens in the CPU; the monitor and printer only present the results.
Thinking a USB port and an HDMI port are interchangeable because both are rectangular.
They are different standards with different shapes and jobs: USB is general-purpose data and power for peripherals, while HDMI carries video and audio to a display.
Believing Bluetooth and USB are competing versions of the same thing.
USB is a wired connection and Bluetooth is a short-range wireless one; a single device can even offer both, and you pick whichever fits the situation.
Treating a scanner and a printer as the same device because they both handle paper.
A scanner is an input device that turns paper into a file; a printer is an output device that turns a file into paper. A multifunction unit simply packages both.
Easily confused
Input device vs. Output device
An input device moves data from the user into the computer; an output device moves processed data from the computer back to the user.
USB vs. HDMI
USB is a general-purpose wired connection for peripherals that carries data and power; HDMI is a specialized cable that carries digital video and audio to a display.
Wired connection (USB, HDMI, audio jack) vs. Wireless connection (Bluetooth)
A wired link uses a physical cable and port; Bluetooth links devices over short-range radio with no cable, after the two devices pair.
Peripheral vs. CPU / RAM / storage
Peripherals surround the computer and handle input and output; the CPU, RAM, and storage are the core components that process and hold data.
Key vocabulary
- Peripheral
- A hardware device that attaches to a computer and sits outside its core processor and memory, used to get information in or out.
- Input device
- Hardware that captures data or control signals from the user or environment and sends them into the computer, such as a keyboard or microphone.
- Output device
- Hardware that takes processed information from the computer and presents it to a person, such as a monitor, printer, or speaker.
- Port
- A physical socket on a computer through which a cable connects a peripheral.
- USB (Universal Serial Bus)
- A widely used Plug and Play wired standard for connecting peripherals and carrying both data and power.
- HDMI (High-Definition Multimedia Interface)
- A connector standard that carries digital video and audio together over a single cable, used to link a computer to a display or projector.
- Bluetooth
- A short-range wireless standard, operating in the 2.4 GHz band, used to connect peripherals such as headphones, keyboards, and mice without a cable.
- Plug and Play
- A design that lets a computer recognize and configure a connected device automatically, without manual setup for each one.
- Touchscreen
- A display that also senses touch, so it works as both an output device and an input device.
Sources & references
- Computer Devices (Information Literacy) — Computer Concepts — Lumen Learning / LibreTexts
- Universal Serial Bus (USB) — Windows drivers — Microsoft Learn
- Bluetooth Technology Overview — Bluetooth SIG
- What is HDMI? — HDMI Specification — HDMI Licensing Administrator (HDMI.org)
EliExplains lessons are original prose written from the open, credible references above. See Copyright & Licensing.
Researched 2026-08-19
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