The questline is very simple.
A power supply is an electronic device that supplies electric energy to an electrical load.
Different types of Power supply
Linear power supply
Unregulated liner power supply
An unregulated linear power supply is the most rudimentary type, consisting of a transformer, rectifier, and low-pass filter
Regulated liner power supply
A regulated liner power supply regulates the output voltage by dropping excess voltage in a series dissipative component. They use a moderately complex regulator circuit to achieve very low load and line regulation. Linear regulated power supplies also have very little ripple and very little output noise.
Example :
Shunt regulators https://www.radio-electronics.com/i...su/shunt-voltage-regulator-theory-circuit.php
Series Regulators https://www.radio-electronics.com/i...u/series-voltage-regulator-theory-circuit.php