Each domain that is registered and hosted has a great deal of DNS records - some of them are set up automatically when you host a domain, others can be created manually if required. As an illustration, the A record of a domain address is its IP address i.e. this record reveals where the site is located; the MX records show where the e-mails are handled, while through an SRV record you can use a domain for unconventional purposes, including a Voice-over-IP service. The ability to set up and modify specific records allows you to have different services with different companies if, for illustration, your current host provides stable web hosting, but has issues with the email service, or you simply prefer to get a particular service from a particular company. Although you must be able to set up and modify these records freely and with no restrictions as you own a given domain name, lots of companies charge extra to give you this option.