Analog and digital signals

Analog and digital signals are used to transmit information, usually through electric signals. 

In both these technologies, the information, such as any audio or video, is transformed into electric signals. 

The difference between analog and digital technologies is that in analog technology, information is translated into electric pulses of varying amplitude. 

In digital technology, translation of information is into binary format (zero or one) where each bit is representative of two distinct amplitudes.

Example

Analog: Human voice in air, analog electronic devices.

Digital: Computers, CDs, DVDs, and other digital electronic devices.