When you add a domain as hosted in some account, you normally set a pair of Name Servers to direct it to that particular service provider. On their end, 3 records are set up automatically as soon as the Internet domain is added - one A record and two MX records. The former is a numeric address, or IP address, that “tells” the Internet domain where its site is, while the other two are alphanumeric and they show the server that handles the e-mails for that particular domain name. The website and the email hosting are generally considered to be one thing, when they're in fact two different services. Having separate records for them will allow you to have them with different providers if you want. As an illustration, some new company may have exceptional uptime for your site, but you might 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 could get the best of both companies. These records are checked whenever you want to open a site or send an e-mail - either way, the company whose name servers are used for the Internet domain is going to be contacted to retrieve the A and MX records and if you have set records different from their own, the right web/mail server will then be contacted and you will see the needed website or your e-mail is going to be delivered.