A token is a unit of value in an existing blockchain. Tokens do not have their own blockchain but are linked to the blockchain of an existing cryptocurrency. For example, being connected to Ethereum or Bitcoin blockchain. Tokens are generally used to collect IEO or investment funds that can be compared with the public offering of publicly traded companies. The most obvious difference between a cryptocurrency and a token is that cryptocurrencies have their own separate blockchains, while tokens do not have their own blockchain, but are used over existing blockchains.