Domain Name Systems (DNS) serve as the phonebook for the Internet. Information is accessed online through domain names such as nytimes.com and espn.com. Web browsers communicate with each other through IP addresses. DNS translates domain names into IP addresses, so browsers can access Internet resources. When the DNS server returns an IP address, the browser connects to the webpage that appears on your screen. Users are not aware of the background tasks involved in making the system work. If the DNS server is unavailable, the browser cannot acquire the IP address of the website, so it returns an error.