Every registered domain has at least 2 Name Server records that show where it is hosted i.e. by using these records you direct your domain name to the servers of a specific web hosting company. This way, you have got both your website and your e-mails managed by the very same provider. On the lower level of the Domain Name System (DNS), nevertheless, there are lots of other records, such as A and MX. The first one reveals which server deals with the site for a given Internet domain and is always an IP address (18.104.22.168), while the second one shows which server handles the e-mails and is always an alphanumeric string (mx1.domain.com). For example, whenever you type a domain address in your Internet browser, your request is sent through the global DNS system to the company whose NS records the domain name uses and from there you may be sent to the servers of another provider if you have set an IP address of the latter as an A record for your domain. Having different records for the website and the e-mails means that you can have your site and your emails with 2 different providers if you'd like.