Any active domain name that is added in a hosting account has a variety of records that enable it to work properly. In the common case, the name servers (NS records) show the location where the Internet domain is hosted and they're set on the side of the registrar company, but on the lower level there are particular records created through the hosting company like A (IP address of the website/server), MX (e mail server), SRV (using a domain address for non-website purposes on a particular port number like Voice-over-IP), and so on. Having access to these records and by being able to modify them, you may have your website with company A and your emails with company B, for instance. This offers you more overall flexibility since you can choose the best provider for every single one of these services and you do not have to stick to a single company. After you select a hosting company, you have to make certain that you can access all DNS records freely as some providers have an additional fee for this feature.