All crypto tokens have associated data. Some are part of the token contract itself, i.e., internal, and some are external. External metadata is associated with a token using various mechanisms. Via this API we hide the complexity of retrieving all of this metadata and associating it with a token.
Some metadata – a token’s logo, its name, or its symbol – provides alternate ways of identifying a token, but these are purely for the convenience of token holders. Remember that the only reliable way to identify a token is by its contract address! We call this identity metadata.
Besides identity metadata, we have metadata that falls into other categories.
decimals is the number of decimals supported by the token. This is important for developers who need to interpret token prices which are always returned as whole numbers.
creation-block is the block at which the token contract was deployed. That tells us how old a token is.
abi is the token's ABI (application binary interface) which is needed to (1) know how to call token contract functions and (2) decode the data returned by these functions.