DEFINITION of 'Purchasing Power Parity-PPP'. An economic theory that estimates the amount of adjustment needed on the exchange rate between countries in order for the exchange to be equivalent to each currency's purchasing power.
Thomas Edison's most famous invention, the lightbulb, paved the way for modern life.
Thomas Edison was an inventor. The definition of an inventor is a person who comes up with an idea for something new. An example of an inventor is Alexander Graham Bell who invented the telephone. inventor.