# 了解区块链 Blockchains enable us to store information on millions of devices globally. With the right consensus models, naming protocols can avoid the need to trust back-end servers to resolve queries, which helps avoid DNS censorship attacks and ensure that internet users land on the web pages they intended to visit. ## Block What is a block? ## Block time It takes on average 10 minutes to mine each Handshake block. With that being said, 1 Handshake block time is = 10 minutes. ## Mining fee Currently Handshake mining fees are less than a penny. ## Nodes What are full nodes? ## Keys What are private and public keys? ## Private Wallet What's a private wallet and why do they matter? --- # 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://learn.namebase.io/cn/about-handshake/blockchain-refresher.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.