Introduction to Electronics.

The concepts of electronics are voltage, current, resistance, capacitance, and inductance, and their components are resistors, capacitors, inductors, and transformers. 

The discrete active circuits include diodes and transformers. 

The I/O elements are transducers. The input goes from physical signals to electrical signals. The output goes from electrical signals to physical signals. 

The discrete passive circuits are the current limiter, the voltage divider, the filter circuits, and the attenuators. 

The discrete active/passive circuits are regulators, amplifiers, oscillators, modulators, mixers, and rectifiers.

Digital circuits only has 2 states, whereas analog circuits can have many states.

A digital integrated circuit can consist of logic gates, flip flops, shift counters, and other various items. Theses are the "brains" of the circuit world, and operate with Analog to Digital circuits, and others. 

The practical components of circuits are multilayer oscilloscopes, schematics, and breadboards.