# Public Addresses A **Public Address** for a [self-custody wallet](/glossary/definitions/self-custody-wallets.md) is a unique string of letters and numbers that is used to receive and send transactions on the [blockchain](/glossary/definitions/decentralization/blockchains.md). A public address is similar to a bank account number, and it can be shared with others in order to receive payments. A public address is derived from the user's [private key](/glossary/definitions/self-custody-wallets/private-keys.md), which is a secret code that is used to access and spend the user's cryptocurrencies. The private key is used to generate the public address, and the two are mathematically linked, but the private key must never be shared with anyone. When a user wants to receive a payment in cryptocurrency, they share their public address with the sender. The sender then uses their own private key to initiate a transaction on the blockchain, sending the funds to the recipient's public address. The recipient can then use their private key to access and spend the funds. --- # 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.allforone.app/glossary/definitions/self-custody-wallets/public-addresses.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.