Any time you add a domain name as hosted in some account, you usually set a pair of Name Servers to direct it to that specific service provider. On their end, three records are created automatically the moment the domain name is added - one A record and two MX records. The first one is a numeric address, or IP address, that “tells” the domain address where its website is, while the other two are alphanumeric and they indicate the server that manages the e-mails for that particular Internet domain. The website and the email hosting are generally thought to be one thing, while they're in reality two different services. Having separate records for them will allow you to have them with different companies if you wish. As an illustration, some new provider can have superb uptime for your website, but you might not want to switch your e-mail messages from your current host and by employing an A record to point the Internet domain to the former and MX records to have the emails with the latter, you will get the best of both companies. These records are checked when you wish to open a website or send an email - either way, the company whose name servers are used for the domain address 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 e-mail will be delivered.