Each registered domain
has at least 2 Name Server records which show where it is hosted i.e. by using these records you point your Internet domain to the servers of a certain web hosting provider. In this way, you have both your site and your e-mails managed by the exact same company. On the lower level of the Domain Name System (DNS), however, there are a number of other records, such as A and MX. The first one shows which server manages the website for a given Internet domain and is always an IP address (18.104.22.168), while the second one reveals which server manages the emails and is always an alphanumeric string (mx1.domain.com). As an illustration, any time you enter a domain in your Internet browser, your request is forwarded through the global DNS system to the provider whose NS records the domain name uses and from there you could be sent to the servers of a different provider if you have set an IP address of the latter as an A record for your domain address. Having separate records for the site and the emails means that you could have your website and your e-mails with two different companies if you wish.