> For the complete documentation index, see [llms.txt](https://unium.gitbook.io/unium/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://unium.gitbook.io/unium/untitled/transaction-fee-gas-fee.md). # Transaction fee (gas fee) 1. What is a transaction fee (gas fee)? When a transaction or contract occurs within the Ethereum platform, the content is transmitted and recorded on the blockchain. However, since this blockchain can be used by anyone, if it overheats, it becomes overloaded, and to prevent this, a “gas fee” is charged. Since all participating processes such as NFT creation, bidding, purchase, and sales are recorded on the blockchain, a fee (gas fee) is incurred in this process. The higher the gas fee is, the higher the priority of work processing. You can check the current gas price at What is Gwei? You can understand it as the smallest unit of Ethereum. ​ 2\. What is Etherscan? EtherScan is a site where you can view data related to pending or confirmed Ethereum blockchain transactions. Since Ethereum is an open, public blockchain, transactions are recorded as they occur and can be viewed by anyone. All information on the Ethereum blockchain is public, but only the public wallet address is shown. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## 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, and the optional `goal` query parameter: ``` GET https://unium.gitbook.io/unium/untitled/transaction-fee-gas-fee.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. 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.