Any time 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, three records are created automatically the moment the Internet domain is added - one A record and two MX records. The former is a numeric address, or IP address, which “tells” the Internet domain where its website is, while the other two are alphanumeric and they reveal the server that handles the e-mails for that particular domain address. The site and the e-mail hosting are often thought to be one thing, when they are in fact two different services. Having separate records for them will allow you to have them with different providers if you wish. For instance, some new company can have excellent 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 domain name to the former and MX records to have the e-mails with the second, you can get the best of both companies. These records are checked when you want to open a website or send an email - either way, the provider 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 will see the needed website or your email will be delivered.