What is ERC-20 called?

Could you please elaborate on the term "ERC-20"? As a cryptocurrency and finance expert, I'm curious to know more about this specification. ERC-20 seems to be a fundamental concept in the blockchain and Ethereum ecosystem, but I'd like to have a deeper understanding of its significance and applications. Could you explain its origins, the key features it encompasses, and how it affects the development and usage of Ethereum-based tokens? Additionally, how does ERC-20 contribute to the overall growth and advancement of the cryptocurrency industry? Your insights would be greatly appreciated.