How does Thomas Alva Edison's light bulb work?

Answer 1

Michael Faraday's made a light bulb with a platinum wire, he put it in a small glass globe, and attached it to a low voltage source. it glowed and produced light.

Platinum is expensive. It only worked at low voltage.

Others made lightbulbs.

Edison decided a light bulb was a good idea but it needed to be made inexpensively. It needed to work at a higher voltage. The source of the electricity needed to be different from the place where the light bulb would be used.

He looked for a material that could be made inexpensively and could last. It needed to be able to take higher voltage. He heated some thread until it turned to carbon. Then he made a vacuum inside a light bulb. He put the thread inside the bulb. It worked.

He created a light bulb. It could be made inexpensively. It could work at a fairly high voltage.