Term | Definition |
input device | Any hardware component that enables you to perform input operations. |
keyboard | A grid of keys used to enter text characters (letters, numbers, and symbols) and to issue commands. |
alphanumeric keyboard | A keyboard that has both letters (alpha-) and numbers (-numeric). |
QWERTY layout | The standard English keyboard layout, named for the first five letters in the top row of letters on the keyboard. |
virtual keyboard | A software-generated, simulated keyboard on devices with a touchscreen, such as a tablet PC or smartphone. |
touchscreen | A touch-sensitive display that is produced by laying a transparent grid of sensors over the screen of a monitor. |
pointing device | An input device that moves an onscreen pointer (usually an arrow). |
mouse | A handheld pointing device that you move across a flat surface (like a desk) to move the onscreen pointer. |
trackball | A stationary pointing device with a ball that you roll with your fingers to move the pointer. |
touchpad | A small, rectangular pad that’s sensitive to pressure and motion, used as a pointing device. Also called track pad. |
graphics tablet | An input device that uses a grid of sensors to record drawing and handwriting using a stylus. |
stylus | A handheld wand that resembles an inkless pen and that is used with a graphics tablet to record handwriting and drawing. |
scanner | A light-sensing device that detects and captures text and images from a printed page. |
digitized information | Data that has been converted to digital format (that is, stored as a string of numeric values). |
charge-coupled device (CCD) | The sensor that records the amount of light reflected from the scanned image in a scanner. |
bitmap | A matrix of rows and columns of pixels. |
pixel | An individual colored dot within a display or a graphic image. |
resolution | On a scanner or printer, the number of pixels recorded or produced per inch; in a display, the number of pixels horizontally and vertically that comprise the display mode. |
dots per inch (dpi) | On a scanner or printer, the number of pixels captured or printed per inch of the original page. |
optical character recognition (OCR) | Specialized software that converts the bitmap images of text to actual text that you can work with in a word-processing or other text-editing program. |
flat-bed scanner | A scanner that has a large, flat, glass-covered surface, similar to a copy machine. |
bar code | A set of black bars of varying widths and spacing that represent data and that can be read by a bar code reader. |
universal product code (UPC) | A bar code on a product for sale, used to provide information about the product at the point of sale and in the store’s inventory. |
bar code reader | A scanner that captures the pattern in a bar code and sends it to an application that translates the pattern into meaningful data. |
digital camera | A camera that captures images in a digital format that a computer can use and display. |
megapixel | One million pixels; a unit of measurement used to describe digital camera resolution. |
digital video camera | A digital camera designed primarily for capturing video; may be portable, like a regular camera, or may be tethered to a computer. See also webcam. |
webcam | A digital video camera that must be connected to a computer to take pictures; commonly used to capture live video that’s streamed via a website. |
audio input | The speech, music, and sound effects that are entered into a computer. |
sound card | The adapter in a computer that translates between the analog sounds that humans hear and the digital recordings of sound that computers store and play back. |
voice input | Technology that enables users to enter data by talking into a microphone connected to the computer. |
voice recognition software | A voice-to-text input program that recognizes preprogrammed words stored in a database, without paying attention to the speaker’s accent or pronunciation. |
speech recognition software | A voice-to-text input program that can be trained to understand a specific person’s voice more accurately by completing a series of practice drills. |
accelerometer | An environmental sensor that reports how fast an object is moving. |
gyroscope | An environmental sensor that describes an object’s orientation in space. |
compass | An environmental sensor that reports the direction an object is pointing in relation to magnetic north. |
global positioning system (GPS) | A device that provides location information by orienting the current location of the device to a signal from an orbiting satellite. |