What is happening when you flip a switch and the light turns on; flip it again, the light goes off. What is it, that let these happen?

In the coming weeks. we will be exploring Electricity and Circuits. We will focus on the following questions:

What is an Electric circuit?

What are Electric circuits, Conductors, and Insulators?

What is an Open and Closed circuit?

What  are the differences between Parallel and Series circuits?

How do we generate and use electricity?

Career in Science: Electrician