When you add a domain name as hosted in some account, you typically set a pair of Name Servers to point it to that specific company. On their end, three records are set up automatically the moment the domain address is added - one A record and two MX records. The first one is a numeric address, or IP address, that “tells” the domain where its site is, while the other two are alphanumeric and they reveal the server that deals with the e-mails for that specific Internet domain. The website and the email hosting are generally considered to be one thing, when they're in fact two different services. Having independent records for them will enable you to have them with different companies if you wish. As an illustration, some new service provider can have exceptional uptime for your site, 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 address to the former and MX records to have the e-mails with the second, you will get the best of both providers. These records are checked whenever you want to open a website or send an e-mail - in either case, the service 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'll see the needed site or your email will be delivered.