Digital information is
stored using a series of ones and zeros. Computers are digital
machines because they can only read information as on or off -- 1 or
0. This method of computation, also known as the binary system, may
seem rather simplistic, but can be used to represent incredible
amounts of data. CDs and DVDs can be used to store and play back
high-quality sound and video even though they consist entirely of
ones and zeros.
Unlike computers, humans perceive information in
capture auditory and visual signals as a continuous stream. Digital
devices, on the other hand, estimate this information using ones and
zeros. The rate of this estimation, called the "sampling rate,"
combined with how much information is included in each sample (the
bit depth), determines how accurate the digital estimation is.
For example, a typical CD audio track is sampled at 44.1 KHz (44,100
samples per second) with a bit depth of 16 bits. This provides a
high-quality estimation of an analog audio signal that sounds
realistic the human ear. However, a higher-quality audio format,
such as a DVD-Audio disc, may be sampled at 96 KHz and have a bit
depth of 24 bits. The same song played on both discs will sound more
smooth and dynamic on the DVD-Audio disc.
Since digital information only estimates analog data, an analog
signal is actually more accurate than a digital signal. However,
computers only work with digital information, so storing data
digitally makes more sense. Unlike analog data, digital information
can also be copied, edited, and moved without losing any quality.
Because of the benefits digital information offers, it has become
the most common way of storing and reading data.
For more information on analog and digital technology, view the
Help Center article.