What are ERC-20 tokens?
ERC-20 tokens are tokens designed and used solely on the Ethereum platform.
They follow a list of standards so that they can be shared, exchanged for other tokens, or transferred to a crypto-wallet.
What is Ethereum, in the first place?
Ethereum is a decentralized network of computers with two basic functions.
They are: blockchain that can record transactions, and a virtual machine that can produce smart contracts.
Because of these two functions, Ethereum is able to support decentralized applications (DApps).
Where do smart contracts fit into all this?
Smart contracts are used to create ERC-20 tokens.
They are also used to facilitate transactions of tokens, and record balances of tokens in an account.
credits:
https://cointelegraph.com/explained/erc-20-tokens-explained
