Any time you add a domain 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 when the domain name 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 indicate the server that handles the e-mails for that specific Internet domain. The website and the email hosting are usually considered to be one thing, while they are actually two different services. Having different records for them will enable you to have them with different providers if you would like. For example, some new provider can have superb uptime for your website, but you might not want to switch your e-mails 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 latter, you could get the best of both providers. These records are checked when you want to open a site or send an e-mail - in either case, the provider 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 correct web/mail server will then be contacted and you will see the needed site or your email is going to be delivered.