Each registered domain name has a minimum of two Name Server records which show where it is hosted i.e. by using these records you direct your domain to the servers of a certain website hosting company. That way, you have got both your website and your e-mails handled by the very same company. On the lower level of the Domain Name System (DNS), however, there is a variety of other records, for instance A and MX. The first one shows which server manages the site for a given Internet domain and is always an IP address (220.127.116.11), while the second one reveals which server deals with the emails and is always an alphanumeric string (mx1.domain.com). As an example, any time you enter a domain address in your Internet browser, your request is sent through the global DNS system to the provider whose NS records the domain address uses and from there you could be directed to the servers of another company if you have set an IP address of the latter as an A record for your Internet domain. Having different records for the website and the e-mails means that you may have your website and your e-mails with 2 different companies if you wish.