An SRV record, which means Service record, is a DNS entry which is used to identify the servers which run a particular service for a domain. In other words, you are able to use your Internet domain not just for a web site, but also for an instant messaging server, a video streaming host or even a Voice-Over-IP server, for instance, while you still have a site with it. If you set up the SRV record, you can select what IP it'll use, on which port the connection to the specific server is going to be established along with the priority and the weight of the record in case that you have a number of SRV records for the very same service. The latter option will enable you to use different machines for load balancing and redundancy. With this type of DNS records, you may use the same domain name many different purposes and even with different companies in case the same one can't provide all services you need.