Every domain name that's registered and hosted has a lot of DNS records - some of them are created automatically when you host a domain, others can be created by hand if required. As an illustration, the A record of a domain address is its IP address i.e. this record reveals where the website is located; the MX records show where the emails are managed, while using an SRV record you can use a domain for unconventional purposes, such as a Voice-over-IP service. To be able to set up and modify particular records enables you to have different services with different providers if, for illustration, your present host provides dependable web hosting, but has difficulties with the email service, or you simply prefer to get a specific service from a particular company. While you should be able to create and edit these records freely and without any limitations as you own a given domain name, a lot of companies charge extra to give you this option.