Whenever you add a domain as hosted in some account, you usually set a pair of Name Servers to direct it to that particular service provider. On their end, three records are set up automatically right after the domain address 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 website is, while the other two are alphanumeric and they reveal the server that handles the e-mails for that particular Internet domain. The website and the e-mail hosting are generally thought to be one thing, while they are in reality two different services. Having different records for them will enable you to have them with different companies if you want. For instance, some new company could have fantastic uptime for your website, but you may not want to switch your e-mail messages from your current host and by employing an A record to point the Internet domain to the first and MX records to have the e-mails with the second, you can get the best of both providers. These records are checked whenever you want to open a site or send an e-mail - in either case, the company 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 site or your e-mail is going to be delivered.