Every single domain name which is registered and hosted has a lot of DNS records - some of them are created automatically when you host a domain, others can be created manually if necessary. As an illustration, the A record of a domain is its IP address i.e. this record shows where the web site is situated; the MX records reveal where the e-mails are managed, while using an SRV record you can use a domain name 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 example, your current host provides dependable web hosting, but has issues with the e-mail service, or you simply prefer to get a certain service from a specific company. Even though you should be able to set up and modify these records freely and with no limits as you own a given domain address, many companies charge extra to give you this option.