(adj.) Also spelled analogue, describes a device or system that represents changing values as continuously variable physical quantities. A typical analog device is a clock in which the hands move continuously around the face. Such a clock is capable of indicating every possible time of day. In contrast, a digital clock is capable of representing only a finite number of times (every tenth of a second, for example). In general, humans experience the world analogically. Vision, for example, is an analog experience because we perceive infinitely smooth gradations of shapes and colors.
When used in reference to data storage and transmission, analog format is that in which information is transmitted by modulating a continuous transmission signal, such as amplifying a signal’s strength or varying its frequency to add or take away data. For example, telephones take sound vibrations and turn them into electrical vibrations of the same shape before they are transmitted over traditional telephone lines. Radio wave transmissions work in the same way. Computers, which handle data in digital form, require modems to turn signals from digital to analog before transmitting those signals over communication lines such as telephone lines that carry only analog signals. The signals are turned back into digital form (demodulated) at the receiving end so that the computer can process the data in its digital format.
Contrast with digital.
- analog monitor
The traditional type of color display screen that has been used for years in televisions. In reality, all monitors based on CRT technology (that is, all monitors except flat-panel displays) are analog. Some monitors, however, are called digital monitors because they accept digital signals from the video adapter. EGA monitors, for example, must be digital […]
- analog roaming
In mobile phone terminology, analog roaming is a feature in digital phones that give users the capability to roam on older analog networks. Because analog networks usually cover a larger distance than digital networks, many are able to use analog roaming in rural areas where digital service may not be available.
- analog television
Preceding digital television (DTV), all televisions encoded pictures as an analog signal by varying signal voltage and radio frequencies. DTV is fast replacing analog TVs as digital broadcasting enables broadcasters to offer television with movie-quality picture and sound. Analog systems are more commonly known as NTSC systems. A U.S. Senate panel has set an April […]
- Analog-To-Digital Converter
(n.) An analog-to-digital converter, or ADC as it is more commonly called, is a device that converts analog signals into digital signals. Analog information is transmitted by modulating a continuous transmission signal by amplifying a signal’s strength or varying its frequency to add or take away data. Digital information describes any system based on discontinuous […]
- anamorphic widescreen
In video terminology, anamorphic widescreen is a process that horizontally squeezes a 16:9 image into a 4:3 space. For the signal to appear with correct geometry, the display must either horizontally expand or vertically squish the image. Anamorphic video is also called “Enhanced for Widescreen” on DVD packaging. [Adapted from Home Theater Magazine]