This article delves into the ERC-20 token standard, a pivotal protocol in the Ethereum blockchain that enables efficient, interoperable, and secure token creation and management. It covers the history, functionality, benefits, and limitations of ERC-20 tokens, clarifying its impact on the blockchain ecosystem. Key problems addressed include interoperability, security, and transparency, appealing to developers and investors. The structure follows an overview of ERC-20, its workings, advantages and limitations, popular tokens, and alternative standards. Suitable for quick scanning, the text enhances understanding of ERC-20's role in blockchain applications.