Every registered domain name has no less than two Name Server records which show where it's hosted i.e. by using these records you point your domain to the servers of a certain website hosting company. In this way, you have got both your site and your emails managed by the same service provider. On the lower level of the Domain Name System (DNS), nevertheless, there are lots of other records, for instance A and MX. The first one reveals which server manages the website for a given domain and is always an IP address (126.96.36.199), while the second one reveals which server manages the emails and is always an alphanumeric string (mx1.domain.com). As an example, whenever you type a domain in your web 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 forwarded to the servers of a different service provider if you have set an IP address of the latter as an A record for your domain address. Having independent records for the website and the e-mails suggests that you may have your website and your emails with 2 different providers if you wish.