An SRV record is a DNS record, that is used to point a domain name to a third-party server and employ it for some service different from a web site. This could be a Voice-Over-IP server, a video streaming service, an instant messaging system, etc. When an SRV record is created, you can specify an Internet Protocol which the domain name will use and the port, that will be used to connect to the remote server. Furthermore, in case you have a few SRV records for the same service, you'll be able to set individual priorities and weights for each one of them, so that you can distribute the load between a number of machines. Such a record will allow you to employ the same domain or subdomains under it with different companies, so you could employ it for many purposes even if you cannot get all services from one service provider.