Examples of such devices are computers, information appliances, digital cameras, digital televisions, flash memory, key USB memory, mobile phones, hard disks, and devices of computer memory. Digital signal processing works on analog signals after they have been converted to digital form.
Digital electronics is a branch of electronics concerning digital circuits which apply boolean logic which are represented by electronic logic gates. True and false are represented by different binary values with 0 volts for true and 5 volts for false. Digital circuits are less vulnerable to noise but consume a lot of energy. Digital circuits were invented in the twentieth century and is the foundation for digital communications and computers.