Interchangeable
Any token of the same kind may be traded for another token of the same kind. To use a fiat currency example, a dollar bill may be substituted for some other dollar bill, and the holder is unaffected.
Non Interchangeable
A non-fungible token cannot be substituted for another non-fungible token of the same kind. When you lend a token to another person, you want the person to return the same token, not another of the same kind.
Uniform
In terms of specification, all tokens of the same form are equivalent; each token is identical to another.
Unique
Each token is distinct from all other tokens of the same kind.
Divisible
Fungible tokens are divisible into smaller units, and it makes no difference which units you get if the value remains constant. In terms of a dollar, it does not matter whether you get a one-dollar note, two fifty-cent bills, or four quarters.
Non-divisible
Tokens that are not fungible cannot be separated. The elementary unit consists of one token and just one token.
ERC-20 standard
The well-known Ethereum blockchain standard that enables the issuance of tokens such as OMG, SNC, TRX, and others.
ERC-721 standard
The new Ethereum blockchain protocol that allows for the development of special, non-fungible tokens. Now, the most well-known use cases are CryptoKitties and other crypto collectibles.