Every website used to be like “www.example.com”. Now I rarely encounter this “www.”. Why did it even exist and where has it gone? I also used to run into websites with legitimate domains, but “ww1.” instead of “www.”, these were probably phishing sites, but how did this actually work on top of legitimate domains?
Domain names are just human-readable addresses for a web server. An A record is just a pointer to the IP address of the web server a given domain name represents. It’s what domain name servers use to tell your browser where it actually needs to send your request.