Following are the fundamental components of electrical circuits :

Active Circuits : Active Circuits are the elements used to generate energy from within their system as a form of source.

Passive Circuits : Passive circuits are the elements that allow the electric current to pass through it and do not generate any energy from it.

AC or DC Circuits : AC stands for Alternating Current, and DC stands for Direct Current. AC always produces some fluctuating current, whereas DC always produces a stable current in a constant source.

Series Circuits : When the electrical components are connected in series within a circuit, it is known as a series circuit.

Parallel Circuits : When the electrical components are connected in parallel within a circuit, it is known as a parallel circuit.