# input-output device

> computer peripheral equipment for input and/or output

**Wikidata**: [Q2384798](https://www.wikidata.org/wiki/Q2384798)  
**Source**: https://4ort.xyz/entity/input-output-device

## Summary  
An **input‑output device** (also called an I/O device) is a piece of computer peripheral equipment that provides either input to, output from, or both functions for a computer system. It sits between the user (or other systems) and the computer, enabling data to be entered, displayed, stored, or transmitted.

## Key Facts  
- **Classification:** Subclass of *peripheral* hardware that attaches to a computer (Wikidata).  
- **Aliases:** Known as input/output device, I/O, dispositivo de E/S, устройство ввода‑вывода, among others.  
- **Part of:** Often considered part of a *computer* (qualifier “sometimes” – P5102).  
- **Facets:** Belongs to the categories *input device*, *output device*, and *human‑machine interface*.  
- **Different from:** Not to be confused with a *computer interface*, *bus*, or *I/O Controller Hub*.  
- **Related entities:** Includes specific models such as *Hitachi CDR‑1503S* and *Sony MDH‑10* (both classified under input‑output devices).  
- **Related concept:** *AlterEgo* – a wearable silent‑speech output‑input device developed by MIT Media Lab.  
- **Metadata:** Wikidata description – “computer peripheral equipment for input and/or output”; Google Knowledge Graph ID /g/121t5tnz.  
- **Commons category:** “Input/output devices”.  

## FAQs  
### Q: What is an input‑output device?  
**A:** It is a peripheral hardware component that either sends data to a computer (input), receives data from a computer (output), or does both.  

### Q: How does an input‑output device differ from a pure input or output device?  
**A:** Pure input devices only provide data to the computer (e.g., keyboard), while pure output devices only convey data from the computer (e.g., monitor). An input‑output device can perform both roles, such as a touchscreen that both displays information and registers touch.  

### Q: Can you give examples of input‑output devices?  
**A:** Examples include optical disc drives like the *Hitachi CDR‑1503S* and *Sony MDH‑10*, as well as hybrid devices such as the *AlterEgo* wearable that both captures silent speech (input) and provides silent feedback (output).  

### Q: Are input‑output devices considered part of the computer itself?  
**A:** They are peripheral devices that attach to a computer; they are sometimes regarded as part of the overall computer system (qualifier “sometimes”).  

### Q: What categories does an input‑output device belong to?  
**A:** It falls under the broader classes of *peripheral*, *human interface device*, *input device*, and *output device*.  

## Why It Matters  
Input‑output devices are essential bridges between humans (or other systems) and computers. By converting physical actions, sounds, images, or other analog signals into digital data, they enable users to command computers, receive feedback, and interact intuitively. Without I/O devices, computers would be isolated black boxes, unable to accept commands or present results, severely limiting their utility. Over time, the evolution of I/O devices—from simple keyboards and printers to sophisticated touchscreens, voice‑controlled assistants, and immersive VR controllers—has driven advances in usability, accessibility, and productivity across every sector that relies on computing. Their role as *human‑machine interface* components makes them a cornerstone of modern technology, influencing design standards, ergonomics, and the overall user experience.

## Notable For  
- **Dual functionality:** Unlike pure input or output peripherals, it can both receive and transmit data.  
- **Broad classification:** Recognized as a subclass of *peripheral* and a facet of *human‑machine interface*.  
- **Diverse forms:** Encompasses devices ranging from optical disc drives to wearable silent‑speech interfaces.  
- **Standard terminology:** Widely referenced across multiple languages and technical vocabularies (e.g., Russian “устройства ввода‑вывода”, Spanish “dispositivo de E/S”).  
- **Distinct from core bus architecture:** Explicitly differentiated from *computer interface* and *I/O Controller Hub* components.  

## Body  

### Definition and Scope  
- An input‑output device is defined as computer peripheral equipment that handles **input**, **output**, or both.  
- It is a **hardware** component that attaches externally to a computer system.  

### Classification Hierarchy  
- **Peripheral** → *Input‑output device* (subclass).  
- Also classified under **human interface device**, **input device**, and **output device**.  
- Occasionally considered part of the **computer** itself (qualifier “sometimes”).  

### Relationship to Other Entities  
- **Different from**:  
  - *Computer interface* – the logical protocol layer.  
  - *Bus* – the electrical pathways inside a computer.  
  - *I/O Controller Hub* – a chipset that manages multiple I/O devices.  
- **Partially coincident with**: *Peripheral* and *user interface* concepts.  

### Types and Examples  
- **Combined I/O hardware**: Optical disc drives (e.g., *Hitachi CDR‑1503S*, *Sony MDH‑10*) read/write data, acting as both input (reading) and output (writing).  
- **Hybrid interactive devices**: *AlterEgo* – a wearable that captures silent speech (input) and provides silent feedback (output).  

### Technical Identifiers  
- **Aliases** include “I/O device”, “dispositivo I/O”, “УВВ”.  
- **Metadata IDs**: Google Knowledge Graph ID /g/121t5tnz; Encyclopædia Britannica ID technology/input-output-device (peripheral device).  
- **Library vocabularies**: LC/MARC IDs for preservation hardware type and environment function type.  

### Role in Computing Ecosystem  
- Serves as the **gateway** for data exchange between the user/environment and the computer’s processing core.  
- Enables **human‑centred interaction**, supporting accessibility (e.g., speech‑based I/O) and expanding functional capabilities (e.g., multimedia playback).  

## Schema Markup  

```json
{
  "@context": "https://schema.org",
  "@type": "Thing",
  "name": "input-output device",
  "description": "computer peripheral equipment for input and/or output",
  "additionalType": "Peripheral"
}