Any active domain name which is added in a hosting account features a variety of records that permit it to function properly. In the typical case, the name servers (NS records) show where the domain name is hosted and they are set on the side of the registrar company, but on the lower level there are particular records created through the hosting company such as A (IP address of the website/server), MX (email server), SRV (employing an Internet domain for non-website purposes on a certain port number like Voice-over-IP), and many others. Having access to these records and by having the capacity to modify them, you can have your web site with company A and your emails with company B, for instance. This offers you more flexibility since you can choose the best provider for each of these services and you do not have to stick to only one company. Whenever you choose a hosting company, you have to make certain that you have access to all DNS records freely because some companies have an additional fee for this function.