Every single registered domain has no less than two Name Server records that show where it is hosted i.e. by using these records you point your Internet domain to the servers of a particular website hosting company. In this way, you have got both your site and your emails managed by the exact same provider. 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 reveals which server manages the site for a given domain and is always an IP address (188.8.131.52), while the latter shows which server handles the emails and is always an alphanumeric string (mx1.domain.com). For instance, when 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 uses and from there you may be forwarded to the servers of another provider in case you have set an IP address of the latter as an A record for your domain address. Having different records for the website and the emails means you could have your website and your e-mails with two different providers if you wish.