What is the use of Celo?

Could you please elaborate on the purpose and usage of Celo in the realm of cryptocurrency and finance? How does it differ from other blockchain platforms, and what specific problems does it aim to solve? Is there a unique feature or service that Celo offers that sets it apart from its competitors? Additionally, could you provide some examples of how Celo is being used in real-world applications, and what kind of impact it's having on the industry?