Analog vs. Digital

One of the big questions asked by students is, “what is analog and how does it differ from digital recording technology”? The following are examples that explain analog and digital formats and some of the advantages to both:

Analog technology: a wave is recorded or used in its original form. So, for example, in an analog tape recorder, a signal is taken straight from the microphone and laid onto tape. The wave from the microphone is an analog wave, and therefore the wave on the tape is analog as well. That wave on the tape can be read, amplified and sent to a speaker to produce the sound.

Digital technology: the analog wave is sampled at some interval, and then turned into numbers that are stored in the digital device. On a CD, the sampling rate is 44,100 samples per second. So on a CD, there are 44,100 numbers stored per second of music. To hear the music, the numbers are turned into a voltage wave that approximates the original wave.

The two big advantages of digital technology are:

  • The recording does not degrade over time. As long as the numbers can be read, you will always get exactly the same wave.
  • Groups of numbers can often be compressed by finding patterns in them. It is also easy to use special computers called digital signal processors (DSPs) to process and modify streams of numbers (see How CDs Work for a more detailed explanation). (http://electronics.howstuffworks.com/question7.htm)

A fun video explaining analog and digital:

Here is another way of explaining the difference between analog and digital technology?

Computers are digital devices, meaning they perform all calculations using ones and zeros. This method of computing is referred to as the “binary system,” and is the heart of all digital technology. Devices such as hard drives, CD recorders, and Mini DV camcorders are digital devices, and therefore record data digitally, as ones and zeros.

VCRs, tape players, and record players, on the other hand, are analog devices. This is because they record data linearly from one point to another. Imagine a bumpy line moving from left to right — that is what an analog audio recording would look like. Analog devices read the media, such as tapes or records, by scanning the physical data off the media.

For example, a record player reads the bumps and dips in the grooves of the record and translates the information into an audio signal. An audio CD player, however, reads ones and zeros off a compact disc and translates that information into an audio signal. However, the ones and zeros only estimate the actual soundwave, whereas a record player records the exact sound. When you hear terms like “sampling rate” or “bit rate,” these refer to how many times per second the digital signal is sampled. The higher the number, the more accurate the estimate is, which translates into higher quality sound or video.

So why is digital technology used if analog provides a better representation of the recorded information? Well, since computers perform digital computations, they can only work with digital media. Therefore, all analog audio or video media must be converted to digital to work on a computer. Once the information is digital, computers can be used to edit the data and create effects that were never possible with analog media. Digital media is non-linear, which means it can be edited or played back starting at any point, which can be a huge timesaver compared to working with tape. Digital information also does not “wear out” after repeated use like tapes or records do, which results in much better longevity for digital media.

To summarize, a digital signal is an estimation of analog data. Digital recordings are made with ones and zeros, while analog recordings are made with linear bumps and dips. While digital information is not as exact as analog information, it can be used with other digital devices, such as computers, making editing and reproduction of the information easier and faster. Because digital media is more compatible and does not degrade over time, it has become the common choice for today’s audio and video formats. (http://pc.net/helpcenter/answers/difference_between_analog_and_digital)

What’s the difference between analog and digital, and why is the latter word, which originally referred to fingers, now the antithesis of “hands-on”?

An analog is something related to physical quantities (hence the name; analog comes from a Greek word meaning “proportion”): An analog clock, for example, shows the passage of time by measuring it with a “hand” that pivots on a central axis, while a measuring tape represents the length of a tangible phenomenon such as a room’s dimensions.

By contrast, digital refers to a device’s reading of binary units, zeros and ones, to perform functions and to the storage of information as binary units rather than an analog recording medium such as magnetic ribbon. Ironically, however, digit stems from the Latin term digitus, meaning “finger” or “toe.” The path from appendages to algorithms involves the use of fingers to count, thus the extension of the definition of digit to “number below ten.” The use of zeros and tens as the basis of the on-off duality of binary computer systems led the technology to be referred to as digital technology.

Indeed, the word bit, referring to the basic unit of digital information, is a contraction of the phrase “binary digit.”

The adjective digital now refers both to something done or having to do with fingers (for example, “digital manipulation”) and something related to digitally rendered numbers, or to computerized data or to electronics. Two other terms with the same root word are digitalis, referring to a plant popularly known as the foxglove and to a medicine extracted from it, and prestidigitation, a sesquipedalian synonym for magic.

Digitalis is a Latinized form of the German word fingerhut (“thimble”), because of the resemblance of the plant’s flowers to the sewing implement.Prestidigitation, meanwhile, is another Latin-looking invention influenced byprestige, which comes from the Latin word praestigiae, “juggler’s tricks.” (Prestige acquired a laudatory meaning and connotation only in the early twentieth century.) It’s a combination of the Italian word presto and digit — hence, “quick fingers.”

Analog, meanwhile, calls to mind its full-form predecessor analogue (which spelling for the adjectival form is also preferred in British English), which means “something similar.” An analogy is also a similarity, or it can refer to a correspondence or to another form of comparison. Analogous is the adjectival form. (http://www.dailywritingtips.com/analog-vs-digital/)

Final Example: http://www.diffen.com/difference/Analog_vs_Digital

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