A DNS server, also known as a DNS resolver, is a server that contains a database of public DNS records and their associated hostnames.
DNS servers are dedicated to answering DNS queries, such as retrieving an IP address associated with a domain name. A combination of internet service providers (ISPs), government organizations, and private businesses (such as Google) are responsible for maintaining these servers.
Browsers use DNS clients that are typically built into operating systems to interact with DNS servers. DNS servers receive DNS queries from DNS clients. For example, if you want to access the hostname example.com, your web browser sends a DNS query containing the hostname to a DNS server. The DNS server then returns the IP address associated with example.com so your browser can connect to the website.
Maintaining consistently updated DNS records for domains across this internet is important because IP addresses and other DNS information changes frequently. The same IP address used to reach example.com today may not be the same address tomorrow.