Data can be stored as binary.
Circuits
The exact workings are complex - a level of abstraction is needed to work with components. The complexity can be studied, but it would be counterproductive to do it for every component discovered. Rather, focus on components critical to your design.
Battery
Voltage and Current
foundations in chemistry
Sensors
detect
Actuators
do
Switches
Mechanical
Electronic
Transistor
Micro Controller
Memory
CPU
Clock
Logic Circuits
NAND
Traditional Computer/Microcontroller
Computer vs microcontroller.