When you add a domain as hosted in some account, you normally set a pair of Name Servers to direct it to that specific company. On their end, 3 records are set up automatically right after the Internet domain is added - one A record and two MX records. The former is a numeric address, or IP address, that “tells” the domain name where its website is, while the other two are alphanumeric and they reveal the server that handles the e-mails for that particular Internet domain. The site and the e-mail hosting are often thought to be one thing, when they are in reality two different services. Having independent records for them will permit you to have them with different providers if you want. As an example, some new company could have exceptional uptime for your site, but you might not want to switch your e-mails from your current host and by employing an A record to point the domain to the first and MX records to have the e-mails with the latter, you could get the best of both companies. These records are checked when you wish to open a website or send an e-mail - in any case, the provider whose name servers are used for the domain name 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 will see the needed site or your e-mail will be delivered.