(n.) An analog-to-digital converter, or ADC as it is more commonly called, is a device that converts analog signals into digital signals. Analog information is transmitted by modulating a continuous transmission signal by amplifying a signal's strength or varying its frequency to add or take away data. Digital information describes any system based on discontinuous data or events. Computers, which handle data in digital form, require analog-to-digital converters to turn signals from analog to digital before it can be read. One example is a modem which turns signals from digital to analog before transmitting those signals over communication lines such as telephone lines that carry only analog signals. The signals are turned back into digital form (demodulated) at the receiving end so that the computer can process the data in its digital format.