A DNS failure occurs when the Domain Name System cannot resolve a domain name into its corresponding IP address. This can happen due to various reasons, such as server outages, misconfigurations, or network issues. When a DNS failure occurs, users may experience difficulties accessing websites, as their browsers cannot locate the server hosting the desired content. In many cases, a DNS failure can be temporary and may resolve itself once the underlying issue is fixed. Users can also troubleshoot by clearing their DNS cache or switching to a different DNS server, such as Google Public DNS or Cloudflare DNS, to regain access to websites.