When you add a domain name as hosted in some account, you typically set a pair of Name Servers to direct it to that specific provider. On their end, 3 records are created automatically when the Internet domain is added - one A record and two MX records. The former is a numeric address, or IP address, which “tells” the domain name where its website is, while the other two are alphanumeric and they indicate the server that manages the e-mails for that particular domain name. The site and the email hosting are often thought to be one thing, while they are in reality two different services. Having separate records for them will enable you to have them with different providers if you wish. As an example, some new service provider can have fantastic uptime for your site, but you may not want to switch your emails from your current host and by employing an A record to point the domain name to the first and MX records to have the emails with the second, you can get the best of both companies. These records are checked when you want to open a site or send an email - in any case, the provider whose name servers are used for the domain will be contacted to retrieve the A and MX records and if you have set records different from their own, the correct web/mail server will then be contacted and you will see the needed site or your e-mail will be delivered.