Analog refers to a non-digital continuous waveform signal, which may contain an infinite number of points along a frequency range. Imagine a lake with the wind blowing across it. There are waves which all connect in a seamless, undulating line which can be drawn over the surface of the water. From a baseline the waves form peaks which rise above the baseline and troughs which sink below it. This is the same as an analog signal, a continuous line with peaks and troughs rising above and sinking below a baseline just like the waves on the lake. The smooth wave contrasts to digital, which is composed of discrete bits or chunks of information (ones and zeroes) which can approximate a waveform but do not create the same signal with the smooth, continuous flow representative of analog signals. nalog signals are used by amplifiers and speakers to recreate sound waves, which are themselves analog signals. All sound waves are continuous analog waveforms. Speakers produce such waves by moving their drivers in the proper frequency to move the air and excite it to recreate the waveform. Digital signals from formats such as CDs and DVDs are converted from their digital form into an analog form in order for the amplifier and speaker to recreate sound (sound waves cannot be created from digital data without first being converted or changed into analog since sound waves themselves are analog). This is accomplished through the use of a digital-to-analog converter or DAC.