Every single registered domain name has a minimum of two Name Server records which show where it's hosted i.e. by using these records you point your Internet domain to the servers of a specific website hosting provider. In this way, you have got both your site and your e-mails managed 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 former reveals which server deals with the website for a given Internet domain and is always an IP address (126.96.36.199), while the second one shows which server deals with the e-mails and is always an alphanumeric string (mx1.domain.com). As an illustration, any time you enter a domain name in your Internet browser, your request is forwarded through the global DNS system to the company whose NS records the domain name uses and from there you could be sent to the servers of another company if you have set an IP address of the latter as an A record for your domain name. Having different records for the site and the emails means that you could have your website and your emails with two different providers if you wish.