# Channels concept Unlike [invoices](/invoices/invoices-concept.md), channels are essentially permanent addresses assigned to each of your end-users. Once created, a channel can be reused by the end-user whenever they want to make a deposit. {% hint style="warning" %} Avoid assigning a single channel to multiple end-users, as it will prevent you from identifying which user sent the funds. Unlike fiat transactions, cryptocurrency transactions do not carry references over the blockchain. By giving each customer their own unique channel, you can easily match their deposits with their account on your platform. {% endhint %} Merchants can create either crypto-to-crypto or crypto-to-fiat channels. For crypto-to-fiat channels, no exchange rate is fixed for 20 minutes as with other transactions. Instead, the exchange rate is determined at the time the transaction is confirmed on the blockchain. Once confirmed, the cryptocurrency is converted to fiat and credited to the merchant's account on Txn. A single channel can receive multiple deposits. Txn emits webhook messages for each transaction detected and received at the channel address. These messages contain data such as the channel ID and reference, deposit ID, crypto transaction amount and hash, exchange rate, credited amount, and timestamps. --- # 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.txn.io/channels/channels-concept.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.