Token
1. Currency - money.
An object - such as a coin, banknote or digital equivalent - whose validity can be identified.
Invalid tokens include counterfeit physical currency.
Invalid physical tokens are ones that have already been spent.
The alternative to token-based money systems is an account-based system.
2. Blockchain.
In the context of blockchain, a token is a unit of value that only exists as a registry entry in the blockchain.
Blockchain tokens are often issued by start-up tech or crypto businesses.
The blockchain tokens are issued with the intention that they be sold or exchanged for conventional currency or cryptocurrency in due course, to fund further development of the start-up project.
Unlike cryptocurrency coins, tokens do not have their own blockchain.
3. Security systems - authentication.
A physical item held by a user of a security system, as an element of identifying them and confirming their authority to use the system.