A DNS resolver is a crucial component of the Domain Name System that translates human-friendly domain names, like www.example.com, into machine-readable IP addresses, such as 192.0.2.1. When you enter a website address in your browser, the DNS resolver queries various servers to find the corresponding IP address, allowing your device to connect to the desired website. Typically, a DNS resolver operates as part of your Internet Service Provider (ISP) or can be a public resolver like Google Public DNS. It caches the results of previous queries to speed up future requests, improving overall browsing efficiency and reducing the load on DNS servers.