Thomas Alva Edison is often credited with inventing the lightbulb, but several other inventors created their own versions before Edison introduced his to the market. Edison gets the credit because his lightbulb was the first practical bulb that also had an electrical system to power it.
The idea for the lightbulb came from the arc lamp, which was invented by Humphrey Davy in 1806. The lamp used charcoal rods to create a very bright electrical spark. The spark was too bright to use in homes and businesses, so other inventors set out to create something that would not produce such a bright light. Frederick DeMoleyns and J.W. Starr both patented bulbs, but their bulbs could not produce light for an extended period of time. Edison's incandescent bulb had long, thin filaments that reduced electrical resistance and increased the life of the bulb, making it more practical than earlier versions.