How does DNS resolution translate URLs into IP addresses?

DNS resolution translates URLs into IP addresses by mapping the human-readable web address to the server's unique IP address.

The Domain Name System (DNS) is a fundamental part of the internet's infrastructure, acting as a directory for devices and the IP addresses associated with them. When you type a URL into your web browser, the DNS resolution process begins. This process involves several steps to translate the URL into an IP address that your computer can understand and use to retrieve data from the correct server.

The first step in this process is your computer checking its local DNS cache, which stores information about recent DNS lookups. If the URL's IP address is in the cache, the process ends here. If not, the request moves to the next stage.

The DNS query then goes to a recursive DNS server, typically operated by your internet service provider (ISP). This server has its own cache, and if it doesn't have the required information, it sends the query to a root DNS server. The root server doesn't know the IP address, but it can direct the query to a Top-Level Domain (TLD) server, which holds information about domains under a specific domain extension, like .com or .org.

The TLD server then points the query to an authoritative DNS server, which holds the actual DNS records for the specific domain. These records include the IP address associated with the domain name. The authoritative server sends this IP address back to the recursive server, which stores the information in its cache for future queries and sends it back to your computer.

Finally, your computer stores the IP address in its local DNS cache and sends the IP address to your browser. The browser then initiates a connection with the server at that IP address to retrieve the web page you requested. This entire process happens in milliseconds, making it seem instantaneous to the user.

In summary, DNS resolution is a multi-step process involving several servers, each playing a crucial role in translating a URL into an IP address that your computer can use to retrieve data from the internet.