When you add a domain name as hosted in some account, you typically set a pair of Name Servers to point it to that specific provider. On their end, three records are set up automatically as soon as the domain address is added - one A record and two MX records. The former is a numeric address, or IP address, that “tells” the domain address where its site is, while the other two are alphanumeric and they show the server that handles the e-mails for that specific Internet domain. The website and the email hosting are typically regarded as one thing, while they are in fact two different services. Having separate records for them will allow you to have them with different providers if you wish. As an example, some new company could have excellent uptime for your site, but you may not want to switch your e-mail messages from your current host and by employing an A record to point the domain address 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 wish to open a site or send an e-mail - in either case, the provider whose name servers are used for the domain will be contacted to retrieve the A and MX records and if you've set records different from their own, the correct web/mail server will then be contacted and you'll see the needed website or your email is going to be delivered.