# Dictionary ### Admin key Admin keys (previously called Auth keys) are keys that have full authority of a contract-based account. Admin keys can add or remove other admin keys. Admin keys should be fully secured. ### Auth key See [Admin key](/dictionary.md#admin-key). ### Dapp key Dapp keys (previously called Login keys) are ephemeral keys generated when logging in to dapps. Dapp keys can only be used for signing transactions. Dapp keys may have more restrictions to provide more security on questionable dapps. Dapp keys cannot add or remove admin keys. ### Login key See [Dapp key](/dictionary.md#dapp-key). ### Relayer A relayer is a service that attaches the gas fee for a transaction. The relayer is typically refunded by the original transaction signer. Some relayers accept the refund to be in a token instead of ETH. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.authereum.com/dictionary.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.