What is meant by Digital electronics?

Answer 1

it deals with logic 1 and logic o where logic 1 is represented by a voltage and the other is also represented by a voltage
There are both digital and analog electronic devices. Digital devices use a binary input - that is, the electrical signals they use to perform functions are in one of two states - a predetermined high or low voltage threshold (sometimes referred to as "on" or "off, 1 or 0 or True or False).

Compare that to analog devices which receive electrical input that use either a constant, direct current, such as that supplied by a battery without any conversion process, or from an alternating current, such as that supplied by your home outlet. The alternating current rises and falls gradually through a series of different states (voltages), rather than the abrupt on/off states that digital equipment requires.

In reality, many electronic devices use a combination of both analog and digital input to accomplish a variety of tasks. For instance, your computer's fan may use an analog signal, while it's processor relies on digital signals to produce output.