The word DIGITAL describes any system based on discontinuous data or events. The important word here is discontinuous, which means not continuous or having breaks. The opposite of digital is analog. 

ANALOG processes information more or less in a continuous stream. The difference can be easily seen in a clock. An analog clock is one with hands that move around the clock continuously producing a stream of time. Any minute and any fraction of a minute can be represented. For instance, you could look at an analog clock and say with some degree of accuracy that it is one and one half minutes past one o'clock. You could see that the minute hand was half way between one and two minutes. The average digital clock, which shows the time by flashing the hour and the minute, produces distinct minutes but cannot represent a half of a minute or a quarter of a minute. The digital clock will show that it is one minute past one or two minutes past one. You cannot tell from looking at the clock if it is one and one half minutes past one or one and a quarter minutes past one.

From the above description, you may surmise that analog is more detailed than digital, but that assumption would be incorrect. Although the normal digital clock will show only minutes, a more detailed digital clock could show fractions of minutes – even a thousandth or millionth of a second, something that an analog clock could not do as accurately. Digital equipment can accurately produce minute details. In addition, digital processing is important because a computer or other digital piece of equipment can store and manipulate digital signals quickly and easily. In addition, digital signals can be converted to analog signals to create a very high quality reproduction.

Computers are digital machines because at the most basic level they can distinguish only two values, zero and one, or off and on. There is no way to represent values in between, such as one-half. All data that a computer processes must be encoded digitally as a series of zeroes and ones. But by combining many of these on-off sequences in complex ways, computers simulate analog events.

Human beings actually process information in an analog manner. We see and hear events in a sort of stream. Vision, for example, is an analog experience because we perceive infinitely smooth gradations of shapes and colors. Most analog events, however, can be simulated digitally.

A newspaper photograph, for instance, consists of an array of dots that are either black or white. From afar, the viewer does not see the individual dots (the digital form), but only lines and shading, which appear to be continuous. Although digital representations approximate analog events, they are useful because they are relatively easy to store and can be manipulated electronically.

The trick is converting analog to digital, and back again. This is the principle behind compact discs (CDs). The music itself exists in an analog form, as waves in the air. These sounds are then translated into a digital form that is encoded onto the disk. When you play a compact disc, the CD player reads the digital data, translates the data back into a voltage wave that approximates the original analog waveform, and sends it to the amplifier and eventually the speakers.  

Digital is the wave of the future because it gives us an accurate way to represent data and an easy way to mechanically store and manipulate that data. Two other advantages of digital technology are the recording does not degrade over time and the digitized information can often be compressed. The move into a digital world is inevitable so I hope this explanation will help you to understand the digital concept.