Analog electronics deals with Analog signals which are continuous signals and vary continuously with time. Most of the signals are analog in nature. In contrast, Digital electronics is where signals usually take only two levels[ON/OFF, HIGH/LOW..]. Digital Electronics deals with digital signal which is discrete signal. Analog and digital circuits are primarily used to transmit and process the information like sound, light from an environment to generate continuous variable signals. To get the outputs, analog circuits can directly give the signals while a digital circuit has to change the information back to an analog signal. Analog and Digital Electronics chapter provides some basic information about analog and digital electronics and circuits.
Primary Difference: The Analog electronic circuit includes an analog signal with any continuously changeable signal. Analog circuit can be used to convert the original signal into some other format such as a digital signal. A digital circuit is a circuit where the signal should be one of two discrete levels. Each level is interpreted as one of two different states (for instance, 0 or 1). This logic is the base of digital electronics & computer processing. Analog circuits can route the signals directly, whereas digital circuits change the analog signals by evaluating them at regular intervals and giving out the resulting values. To get the outputs, analog circuits can directly give the signals while a digital circuit has to change the information back to an analog signal.
The Analog Signals can be converted into Digital by A/D Analog to Digital Converter circuits and vice a versa Digital Signal is converted into Analog by D/A Digital to Analog converter. Analog electronics is the processing of continuous voltages and currents, that can have any values between two limits. Digital electronics is the processing of discrete signals that are associated with numbers.