with discrete each of us faces every day.This is one of the inherent properties of matter.In the literal translation from the Latin word meaning discretus discontinuity.For example, a digital signal - a way to transmit information when the medium-carrier of changes over time, taking any of the existing list of valid values.
Of course, the term "discrete" is used in a broader sense.In particular, progress in microelectronics is now aimed at the creation and development of technology SOC - «The system on a chip."It is assumed that all components constituting the device are tightly integrated with each other on a single substrate.The opposite of this approach - discrete scheme, when the elements are themselves the products completed, connecting links.
Perhaps now it is impossible to find a person who does not use a mobile phone or the Skype program on your computer.One of their tasks - is the transfer of the audio stream (such as voice).But since this is a continuous sound wave for its immediate transmission channel would require high bandwidth.To address this issue was proposed to use a digital signal.Generates he did not wave, and its digital representation (remember, we are talking about mobile phones and computers).With a wave at regular intervals fetches the data values.That is, a discrete signal is created.The advantage is obvious: the smaller the total flow of data and the possibility of organizing packet.The target receiving device combines all the samples in a single unit, generating the original wave.The larger gaps between the samples, the higher the likelihood of distortion of the original wave.Sampling is widely used in computing.
Speaking of what is a digital signal, it is impossible not to take advantage of the remarkable analogy with the conventional printed book.The person reading it receives a continuous flow of information.At the same time, the data contained therein "encoded" in the form of certain sequences of letters - words - sentences.It turns out that the author of the indivisible thought forms a kind of digital signal, since it expresses the division into blocks, using one or another method of encoding (alphabet, language).The reader in this example, is able to perceive the idea of the author only after the mental association of words in the information flow.
Surely, you're reading this on a computer screen.But even the monitor is an example of where manifested discrete and continuous.Remember the old models based on the CRT.They generate a sequence of image frames that are needed to "draw" a few tens of times per second.Obviously, this device uses a method of constructing a binary image.
Digital signal is the antithesis of the continuous.The latter is a function of the intensity of the time (if you imagine it on a Cartesian plane).As already mentioned, one example is a sound wave.It is characterized by frequency and amplitude, but naturally is not interrupted.Most natural processes are described in this way.Despite the fact that, all the same, there are several ways of processing the continuous (or analog) signal allowing to reduce the data stream, in modern digital systems, it is common logic.Partly due to the fact that it can be simply converted into the original, regardless of the configuration of the latter.Incidentally, it is worth noting that the terms "digital" and "digital" is practically equivalent.
