Domain Name
A domain name is a human-readable label that identifies a network resource, such as a web server. It is mapped to an IP address through the Domain Name System DNS.
Domain names appear in URLs, are parsed with parse_url(), and validated with the filter extension using FILTER_VALIDATE_DOMAIN.
<?php
$host = parse_url('https://www.example.com/path', PHP_URL_HOST);
// $host = 'www.example.com'
$isValid = filter_var('example.com', FILTER_VALIDATE_DOMAIN);
?>