When you add a domain name as hosted in some account, you typically set a pair of Name Servers to direct it to that specific company. On their end, three records are created automatically when the Internet domain is added - one A record and two MX records. The first one is a numeric address, or IP address, that “tells” the Internet domain where its website is, while the other two are alphanumeric and they reveal the server that manages the emails for that particular domain. The website and the e-mail hosting are typically considered 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 wish. As an illustration, some new provider might have superb uptime for your site, but you may not want to switch your emails from your current host and by using an A record to point the domain name to the first and MX records to have the e-mails with the latter, you can get the best of both companies. These records are checked when you wish to open a site or send an email - either way, the service 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 right web/mail server will then be contacted and you'll see the needed site or your email is going to be delivered.