What is Token?
A token is an asset issued by a smart contract on an existing chain, as opposed to the chain’s own native coin. Fungible tokens are interchangeable; non-fungible ones are not.
In practice
On EVM chains ERC-20 covers fungible tokens and ERC-721 covers non-fungible ones. What a token actually does matters more than its label: governance rights, fee claims, access, or pure speculation are very different things, and the contract plus distribution schedule is where the answer lives.