An input device is a hardware component used to enter data, instructions, commands, or signals into a computer system. Input devices allow users and the physical environment to communicate with a computer.
When you type using a keyboard, move a mouse, speak into a microphone, scan a document, or touch a touchscreen, you are providing input to the computer.
Some common input devices include keyboard, mouse, scanner, microphone, webcam, touchscreen, touchpad, joystick, trackball, barcode reader, biometric scanner, graphics tablet, OMR, OCR, MICR, RFID reader, and sensors.
How Do Input Devices Work?
Different input devices collect different forms of information, but their basic purpose is similar.
User/Environment → Input Device → Digital Data → Processing → Output
For example, when a user presses a key:
Key Press → Keyboard → Input Signal → Computer → Processing → Character Displayed
A microphone performs a different conversion:
Voice → Microphone → Electrical Signal → Digital Audio Data → Computer
The exact conversion process depends on the input device.
Types of Input Devices
Input devices can be broadly grouped according to the type of information they collect.
Text Input Devices
Used to enter letters, numbers, and symbols.
Example: Keyboard
Pointing Devices
Used to control a pointer or interact with graphical interfaces.
Examples: Mouse, touchpad, trackball
Audio Input Devices
Used to capture sound.
Example: Microphone
Image and Video Input Devices
Used to capture images, documents, and video.
Examples: Scanner, webcam, digital camera
Touch and Pen Input Devices
Used to provide input by touching or writing on a surface.
Examples: Touchscreen, stylus, graphics tablet
Automatic Data Capture Devices
Used to capture encoded or printed information with little manual typing.
Examples: Barcode reader, QR reader, OMR, OCR, MICR, RFID reader
Biometric Input Devices
Used to capture biological characteristics.
Examples: Fingerprint scanner, iris scanner, facial-recognition camera
Sensor Input Devices
Used to collect information from the physical environment.
Examples: Temperature, light, motion, pressure, and proximity sensors
Keyboard
A keyboard is an input device used to enter text, numbers, symbols, and commands into a computer.
It is one of the most widely used computer input devices.
How Does a Keyboard Work?
When a user presses a key, the keyboard detects the physical key press.
Keys are commonly arranged electronically as part of a keyboard matrix consisting of rows and columns.
The keyboard controller identifies the key event and sends information about it to the computer.
The operating system then interprets that input according to the selected keyboard layout and modifier keys.
For example:
Press A → Keyboard detects key → Computer receives event → OS interprets it → “a” appears
Pressing:
Shift + A
can instead produce:
A
Main Types of Keyboard Keys
Alphanumeric Keys
Used to enter letters and numbers.
Examples:
A–Z and 0–9
Function Keys
Usually labelled:
F1–F12
They perform application or operating-system-specific functions.
Modifier Keys
Examples include:
- Shift
- Ctrl
- Alt
- Windows key
- Command key
- Option key
Navigation Keys
Examples include:
- Arrow keys
- Home
- End
- Page Up
- Page Down
Numeric Keypad
A dedicated group of numerical and arithmetic keys commonly found on full-size keyboards.
Types of Keyboards
Common types include:
- Membrane keyboard
- Mechanical keyboard
- Wired keyboard
- Wireless keyboard
- Ergonomic keyboard
- Gaming keyboard
- Virtual keyboard
Mechanical vs Membrane Keyboard
A mechanical keyboard generally uses an individual mechanical switch underneath each key.
A membrane keyboard uses membrane-based electrical contacts.
Mechanical keyboards often provide more distinct feedback and may offer greater durability, while membrane keyboards are generally cheaper and quieter.
Keyboard Ghosting and N-Key Rollover
Ghosting describes problems where certain simultaneous key combinations are not registered correctly or create unintended results.
N-key rollover (NKRO) refers to a keyboard’s ability to correctly register many simultaneous key presses.
Uses of Keyboard
Keyboards are commonly used for:
- Writing documents
- Programming
- Entering passwords
- Data entry
- Gaming
- Searching the internet
- Using keyboard shortcuts
Advantages
- Fast text entry
- Accurate numerical input
- Supports shortcuts
- Excellent for programming
- Relatively inexpensive
Disadvantages
- Requires typing skills
- Occupies physical space
- Poor posture during prolonged use can cause discomfort
- Dust can accumulate between keys
Mouse
A mouse is a pointing input device used to control the pointer on a computer screen.
It allows users to select, open, move, drag, and interact with graphical objects.
How Does a Mouse Work?
Modern mice commonly use optical sensing technology.
A light source illuminates the surface underneath the mouse. A small sensor captures rapid observations of the surface.
Internal processing compares changes between these observations to determine movement.
The basic process is:
Mouse Movement → Sensor → Movement Calculation → Computer → Pointer Movement
Main Mouse Controls
A typical mouse contains:
- Left button
- Right button
- Scroll wheel
- Movement sensor
Advanced mice may contain additional programmable buttons.
Types of Mouse
Common types include:
- Mechanical mouse
- Optical mouse
- Laser mouse
- Wired mouse
- Wireless mouse
- Gaming mouse
- Ergonomic mouse
Optical Mouse
An optical mouse commonly uses LED illumination and an image sensor to detect movement.
Laser Mouse
A laser mouse uses laser illumination and can provide detailed surface tracking.
What Is Mouse DPI?
DPI (dots per inch) is commonly used to describe mouse sensor sensitivity.
Higher DPI generally produces more movement counts for the same physical movement.
However, higher DPI does not automatically mean better performance.
What Is Polling Rate?
Polling rate describes how frequently a mouse reports its state to the computer.
Examples include:
- 125 Hz
- 500 Hz
- 1000 Hz
A 1000 Hz polling rate corresponds to approximately one report every millisecond.
Uses of Mouse
- Navigating graphical interfaces
- Selecting files
- Browsing websites
- Gaming
- Graphic design
- Video editing
- Office applications
Advantages
- Easy to use
- Precise pointer control
- Excellent for graphical interfaces
- Supports scrolling and dragging
Disadvantages
- Requires physical movement space
- Some surfaces can affect tracking
- Wireless models require power
- Poor hand positioning may cause discomfort
Scanner
A scanner is an input device used to convert physical documents, photographs, drawings, or printed information into digital images.
For example, a paper photograph can be scanned and stored as a digital image on a computer.
How Does a Scanner Work?
A scanner illuminates the physical document and uses light-sensitive components to measure the reflected light.
The captured information is converted into digital image data.
The simplified process is:
Physical Document → Light → Sensor → Electrical Information → Digital Image → Computer
Types of Scanners
Flatbed Scanner
The document is placed on a flat glass surface.
It is commonly used for:
- Documents
- Photographs
- Books
- Certificates
Sheet-Fed Scanner
Documents are automatically pulled through the scanner.
They are useful in offices where many loose pages need to be scanned.
Handheld Scanner
A handheld scanner is manually moved across the material being scanned.
Drum Scanner
Drum scanners are specialised high-quality scanning systems historically used where very high image quality and detail are required.
Scanner Resolution
Scanner resolution is commonly expressed in DPI.
A higher optical resolution can capture greater image detail, although it also creates larger files and does not automatically improve a poor-quality original.
Uses of Scanner
- Digitising documents
- Scanning photographs
- Creating electronic records
- Document archiving
- Supporting OCR processing
Advantages
- Converts physical documents into digital form
- Helps preserve records
- Makes documents easier to share
- Useful for electronic archiving
Disadvantages
- High-resolution scans can require significant storage
- Scanning large numbers of pages can take time
- Image quality depends on the original and scanner
Microphone
A microphone is an audio input device that captures sound and converts it into an electrical signal.
For digital computer systems, this signal is ultimately converted into digital audio data.
How Does a Microphone Work?
Sound consists of pressure variations travelling through a medium such as air.
Inside a microphone, a component such as a diaphragm responds to these pressure variations.
The microphone converts these movements into an electrical signal.
For digital recording:
Sound Waves → Microphone → Electrical Signal → Analog-to-Digital Conversion → Digital Audio
Types of Microphones
Common types include:
- Dynamic microphone
- Condenser microphone
- Lavalier microphone
- Headset microphone
- USB microphone
- Built-in microphone
Uses
- Voice calls
- Video conferencing
- Voice assistants
- Podcasting
- Music recording
- Speech recognition
- Gaming
Advantages
- Enables audio recording
- Supports voice communication
- Allows voice-controlled interfaces
- Useful for accessibility technologies
Disadvantages
- Can capture unwanted background noise
- Recording quality varies considerably
- High-quality equipment can be expensive
Webcam
A webcam is an input device used to capture digital images and video, usually for direct use by a computer.
Many laptops contain integrated webcams.
How Does a Webcam Work?
Light enters through the webcam’s lens and reaches an electronic image sensor.
The sensor converts incoming light into electrical information, which is processed into digital image or video data.
Light → Lens → Image Sensor → Digital Processing → Computer
Uses of Webcam
- Video conferencing
- Online classes
- Live streaming
- Video recording
- Facial recognition
- Remote communication
Advantages
- Real-time video communication
- Small and convenient
- Often integrated into laptops
- Useful for remote work and education
Disadvantages
- Image quality varies
- Requires sufficient lighting
- Can create privacy risks if device or software security is compromised
Digital Camera
A digital camera captures photographs or video as digital information.
When connected to or integrated with a computer system, it can act as a source of image and video input.
How Does It Work?
Light enters through the lens and reaches an electronic image sensor.
The camera processes the sensor data and stores the resulting image or video digitally.
Uses
- Photography
- Video production
- Documentation
- Scientific imaging
- Content creation
Touchscreen
A touchscreen is a display that can also detect touch input.
Therefore, a touchscreen can function as both an input and output device.
It outputs visual information while receiving touch input.
How Does a Touchscreen Work?
Different touchscreen technologies detect touch in different ways.
Resistive Touchscreen
A resistive touchscreen uses multiple layers.
Pressure causes conductive layers to make contact, allowing the device to calculate the touch position.
Capacitive Touchscreen
Capacitive touchscreens detect changes in an electrostatic field caused by a conductive object such as a human finger.
Capacitive technology is widely used in modern smartphones and tablets.
Multi-Touch
Multi-touch systems can detect multiple touch points simultaneously.
This enables gestures such as:
- Pinch to zoom
- Two-finger scrolling
- Rotation gestures
Uses
- Smartphones
- Tablets
- ATMs
- Self-service kiosks
- Point-of-sale systems
- Interactive displays
Advantages
- Direct interaction
- No separate mouse required
- Intuitive interface
- Supports gestures
Disadvantages
- Fingerprints can accumulate on the display
- Less comfortable for long text entry
- Physical damage to the screen can affect both input and output
Touchpad
A touchpad is a touch-sensitive pointing device commonly built into laptops.
Users move a finger across its surface to control the pointer.
How Does a Touchpad Work?
Modern touchpads commonly use capacitive sensing.
They detect changes caused by a finger touching or moving across the surface.
Common Gestures
Depending on the operating system and hardware, gestures can include:
- Single tap
- Double tap
- Two-finger scroll
- Pinch to zoom
- Multi-finger application switching
Advantages
- Built into laptops
- Requires little space
- No separate mouse needed
- Supports gestures
Disadvantages
- Some users find it less precise than a mouse
- Less convenient for certain games and design tasks
Trackball
A trackball is a pointing device containing a ball that users rotate with their fingers or thumb.
Unlike a mouse, the device itself remains stationary.
How Does a Trackball Work?
Movement of the ball is detected by internal sensors.
The detected rotation is converted into pointer movement.
Advantages
- Requires little desk space
- Device remains stationary
- Can provide precise control
Disadvantages
- Requires practice
- Can feel unfamiliar
- Ball mechanism may require cleaning
Joystick
A joystick is an input device consisting of a movable stick used to control direction or movement.
How Does a Joystick Work?
Moving the stick changes its position along one or more axes.
Sensors detect these movements and convert them into digital input.
Uses
- Flight simulators
- Video games
- Industrial control systems
- Simulation and training
Advantages
- Good directional control
- Suitable for simulation
- Intuitive for certain games
Disadvantages
- Not suitable for normal text entry
- Requires additional desk space
- Limited usefulness outside specialised applications
Game Controller
A game controller or gamepad is an input device designed primarily for video games.
It may contain:
- Directional pad
- Analogue sticks
- Buttons
- Triggers
- Bumpers
- Motion sensors
Controllers can provide several forms of input simultaneously.
Light Pen
A light pen is a pen-shaped pointing device historically used to interact directly with compatible display systems.
The user could point the device at positions on the display.
Light pens were particularly associated with CRT display technology and are rarely used in modern general-purpose computers.
They should not be confused with modern touchscreen styluses.
Graphics Tablet
A graphics tablet, also known as a digitising tablet, is an input device that allows users to draw or write using a stylus.
It is commonly used by:
- Graphic designers
- Digital artists
- Animators
- Architects
- Photo editors
How Does a Graphics Tablet Work?
The tablet detects the position and movement of a compatible stylus.
Advanced models may also detect:
- Pressure
- Pen angle
- Tilt
- Button input
This information allows software to reproduce natural drawing behaviour.
Advantages
- Precise drawing
- Pressure-sensitive input
- Natural for digital artwork
- Useful for handwriting
Disadvantages
- Requires practice
- Professional models can be expensive
Stylus
A stylus is a pen-shaped input tool used with touchscreens or graphics tablets.
Depending on the technology, an active stylus may provide information such as:
- Position
- Pressure
- Tilt
- Button presses
Styluses are commonly used for:
- Drawing
- Handwriting
- Note-taking
- Digital signatures
- Precise touchscreen interaction
Barcode Reader
A barcode reader is an input device used to read information encoded in barcodes.
Barcodes represent information using patterns that can be detected by a scanner or camera-based system.
How Does a Barcode Reader Work?
The reader detects the barcode pattern and decodes it into data.
That data is then sent to the computer or point-of-sale system.
Uses
- Supermarkets
- Warehouses
- Inventory systems
- Libraries
- Logistics
- Hospitals
Advantages
- Fast data entry
- Reduces manual typing
- Useful for inventory management
- Can reduce data-entry errors
QR Code Reader
A QR code reader reads two-dimensional QR codes.
QR stands for Quick Response.
Unlike traditional one-dimensional barcodes, QR codes can encode information across both horizontal and vertical dimensions.
Modern smartphones commonly use their cameras as QR readers.
Uses
- Website links
- Digital payments
- Product information
- Tickets
- Authentication workflows
- Contact information
Biometric Input Devices
Biometric input devices capture measurable biological or behavioural characteristics that can be used for recognition.
Common biometric systems include:
- Fingerprint recognition
- Facial recognition
- Iris recognition
- Voice recognition
Biometric data is often used for authentication and identity verification.
Fingerprint Scanner
A fingerprint scanner captures characteristics of the patterns found on a person’s finger.
The system extracts useful features from the captured fingerprint and compares them with a stored biometric template.
Types of Fingerprint Sensors
Common technologies include:
- Optical
- Capacitive
- Ultrasonic
Uses
- Smartphones
- Laptops
- Access control
- Attendance systems
- Identity verification
Advantages
- Convenient
- Fast
- Difficult to casually share compared with a password
Disadvantages
- Recognition can sometimes fail
- Sensors can be affected by environmental or finger conditions
- Biometric information requires strong privacy and security protection
Iris Scanner
An iris scanner captures patterns in the coloured region surrounding the pupil of the eye.
Image processing is used to extract features that can be compared with an enrolled biometric template.
Iris recognition is used in some high-security and identity-management systems.
Facial Recognition Camera
A camera can provide facial image data to facial-recognition software.
The software analyses facial features and compares the resulting representation with stored information.
The camera itself captures the input; the recognition algorithm performs the analysis.
OMR – Optical Mark Recognition
OMR (Optical Mark Recognition) is a technology used to detect marked positions on specially designed forms.
A common example is a multiple-choice answer sheet where students fill circles or boxes.
How Does OMR Work?
The system scans predefined locations on the form and determines whether those areas have been marked.
Uses
- Multiple-choice examinations
- Surveys
- Voting or ballot-style forms
- Feedback forms
Advantages
- Processes large numbers of forms quickly
- Reduces manual data entry
- Suitable for standardised forms
Disadvantages
- Requires properly designed forms
- Incorrect or unclear marks may cause errors
OCR – Optical Character Recognition
OCR (Optical Character Recognition) is a technology that converts images containing printed or handwritten text into machine-readable text.
For example, a scanned page is initially an image.
OCR software can analyse that image and extract text that can then be searched, copied, or edited.
OCR Process
Document → Scan/Image → OCR Analysis → Character Recognition → Editable/Searchable Text
Uses
- Digitising books
- Processing invoices
- Extracting text from scanned documents
- Archiving documents
- Automated document processing
Advantages
- Reduces manual typing
- Makes scanned documents searchable
- Helps digitise large document collections
Disadvantages
Accuracy can decrease when documents contain:
- Poor image quality
- Unusual fonts
- Handwriting
- Complex layouts
- Damaged text
Important: OCR is primarily a recognition technology/software process. A scanner or camera provides the physical input, while OCR interprets the captured image.
MICR – Magnetic Ink Character Recognition
MICR (Magnetic Ink Character Recognition) is a character-recognition technology commonly associated with banking documents such as cheques.
Special characters are printed using magnetic ink or toner.
A MICR reader detects and interprets these characters.
Uses
MICR has traditionally been used for information such as:
- Bank routing information
- Account-related identifiers
- Cheque processing information
Advantages
- Designed for fast automated processing
- Reliable for banking workflows
- Magnetic properties can assist reading even when markings are present
Disadvantages
- Requires specialised printing and reading systems
- Primarily useful in specialised financial applications
Magnetic Stripe Reader
A magnetic stripe reader reads information encoded in the magnetic stripe found on compatible cards.
The stripe stores information magnetically.
When the card is swiped through or passed across a reader, the reader detects the encoded magnetic changes.
Uses
Historically and currently in some systems:
- Payment cards
- Identification cards
- Access cards
- Membership systems
Many modern systems increasingly use chips or contactless technologies instead.
Smart Card Reader
A smart card reader communicates with cards containing an integrated circuit chip.
The chip can store and process information.
Smart cards are used in applications such as:
- Authentication
- Banking
- Identification
- Access control
Depending on the system, the reader may support physical electrical contacts or contactless communication.
RFID Reader
RFID stands for Radio Frequency Identification.
An RFID reader communicates with RFID tags using radio-frequency signals.
Main Components
An RFID system generally contains:
- RFID reader
- Antenna
- RFID tag
- Backend computer/database system
How Does RFID Work?
The reader transmits radio-frequency energy or signals.
A compatible tag responds with information that the reader captures and sends to a computer system.
Passive RFID Tags
Passive tags do not contain their own conventional battery power source for communication. They obtain energy from the reader’s electromagnetic field.
Active RFID Tags
Active tags contain their own power source and can generally communicate over greater distances.
Uses
- Warehouse inventory
- Asset tracking
- Supply chains
- Access control
- Logistics
- Retail
NFC Reader
NFC (Near Field Communication) is a short-range wireless communication technology related to RFID technologies.
NFC-capable devices can exchange information when placed very close together.
Uses
- Contactless payments
- Access systems
- Device pairing
- Reading NFC tags
- Digital tickets
A smartphone can function as both an NFC reader and, in supported applications, an NFC communication device.
Sensors
A sensor is an input device that detects or measures a physical property or environmental condition and converts it into information that a computer or electronic system can process.
Sensors are extremely important in modern computing, especially in:
- Smartphones
- Vehicles
- Robotics
- Smart homes
- Industrial systems
- IoT devices
Temperature Sensor
Measures temperature.
Used in:
- Computers
- HVAC systems
- Industrial equipment
- Smart homes
Light Sensor
Measures ambient light intensity.
Smartphones can use ambient light sensors to help automatically adjust screen brightness.
Proximity Sensor
Detects whether an object is nearby.
For example, smartphones can use proximity sensing during calls to help manage touchscreen behaviour.
Motion Sensor
Detects movement.
Used in:
- Security systems
- Automatic lighting
- Smart homes
- Gaming systems
Pressure Sensor
Measures physical pressure.
Used in industrial, automotive, medical, and environmental systems.
Accelerometer
Measures acceleration along one or more axes.
Smartphones use accelerometers for functions such as motion detection and orientation-related features.
Gyroscope
Measures rotational movement or angular velocity.
It can complement accelerometers for more accurate motion and orientation sensing.
GPS Receiver
A GPS receiver receives satellite signals and calculates location-related information.
It provides location input to smartphones, navigation systems, vehicles, and other computing devices.
MIDI Input Devices
MIDI (Musical Instrument Digital Interface) allows electronic musical devices and computers to exchange musical performance information.
A MIDI keyboard can send information such as:
- Which note was played
- When it was played
- How strongly it was played
- When it was released
MIDI data generally represents performance instructions rather than recorded sound itself.
MIDI controllers are widely used in:
- Music production
- Digital audio workstations
- Live performances
- Electronic music
Input Devices vs Output Devices
Input and output devices perform different roles in a computer system.
| Input Devices | Output Devices |
|---|---|
| Send data to the computer | Present information from the computer |
| Keyboard | Monitor |
| Mouse | Printer |
| Microphone | Speakers |
| Scanner | Projector |
| Webcam | Headphones |
Some devices can perform both input and output.
For example, a touchscreen:
Display → Output
Touch detection → Input
A headset can also contain:
Headphones → Output
Microphone → Input
Manual Input vs Automatic Data Capture
Manual Input
The user actively enters information.
Examples:
- Keyboard
- Mouse
- Joystick
- Graphics tablet
Automatic or Direct Data Capture
Information is captured with relatively little manual data entry.
Examples:
- Barcode reader
- RFID reader
- Sensors
- Biometric scanner
- OMR systems
Automatic data capture can improve speed and reduce manual transcription errors.
Common Input Devices and Their Functions
| Input Device | Main Function |
|---|---|
| Keyboard | Enter text, numbers and commands |
| Mouse | Control pointer |
| Scanner | Digitise documents and images |
| Microphone | Capture sound |
| Webcam | Capture images/video |
| Touchscreen | Detect touch |
| Touchpad | Control pointer |
| Trackball | Control pointer using rotating ball |
| Joystick | Directional control |
| Graphics Tablet | Drawing and handwriting |
| Barcode Reader | Read barcodes |
| QR Reader | Read QR codes |
| Fingerprint Scanner | Capture fingerprint characteristics |
| OMR | Detect marked areas |
| OCR | Recognise text in images |
| MICR Reader | Read magnetic-ink characters |
| RFID Reader | Read RFID tags |
| NFC Reader | Short-range wireless data exchange |
| Sensors | Measure physical/environmental conditions |
| MIDI Controller | Enter musical performance data |
Importance of Input Devices
Input devices are essential because computers need a way to receive information from users and their environment.
They allow computers to receive:
- Text
- Numbers
- Commands
- Images
- Video
- Sound
- Touch
- Movement
- Location
- Biometric characteristics
- Environmental measurements
Without input mechanisms, most modern interactive computer systems would have extremely limited ability to respond to users or the physical world.
Frequently Asked Questions About Input Devices
What Is an Input Device?
An input device is hardware used to provide data, instructions, or signals to a computer system.
What Are Five Common Input Devices?
Five common input devices are:
- Keyboard
- Mouse
- Scanner
- Microphone
- Webcam
Is a Keyboard an Input Device?
Yes. A keyboard sends text, numbers, symbols, and commands to a computer.
Is a Mouse an Input Device?
Yes. A mouse sends movement, scrolling, and button information to a computer.
Is a Touchscreen an Input or Output Device?
A touchscreen can perform both functions.
The screen displays information as output, while its touch-sensitive layer receives user input.
Is a Scanner an Input Device?
Yes. A scanner captures information from physical documents or photographs and provides digital image data to a computer.
Is a Microphone an Input Device?
Yes. A microphone captures sound and converts it into signals that can be processed and stored digitally.
Is a Printer an Input Device?
No. A conventional printer is an output device because it receives information from the computer and produces physical output.
What Is the Difference Between OMR and OCR?
OMR detects marks at predefined positions on forms.
OCR recognises characters contained in images and converts them into machine-readable text.
What Is the Difference Between OCR and a Scanner?
A scanner captures a document as an image.
OCR analyses an image to recognise the text contained within it.
Therefore:
Scanner → Captures Image
OCR → Recognises Text
What Are Biometric Input Devices?
Biometric input devices capture biological or behavioural characteristics for recognition.
Examples include fingerprint scanners, iris scanners, and cameras used in facial-recognition systems.
Summary
Input devices are hardware components that allow data, instructions, commands, and signals to enter a computer system.
Different input devices are designed for different forms of information.
Keyboard provides text and command input.
Mouse, touchpad, and trackball provide pointing input.
Scanner and camera systems provide image input.
Microphones provide audio input.
Touchscreens and graphics tablets provide touch or pen-based input.
Barcode, QR, OMR, OCR, MICR, RFID, and NFC technologies support automated or specialised data capture.
Biometric devices capture characteristics used for recognition.
Sensors allow computers to collect information about the physical environment.
Together, these technologies make it possible for computers to interact with users and the world around them.
