SRV, which is an abbreviation for Service, is a DNS record, which allows you to employ a domain name for a certain service different from a website. By setting up a few SRV records, you’re able to use the domain name with different companies and forward it to many servers at once, every single server handling a separate service. You are able to specify the port number for the connection to each and every machine, so there won't be any interference. You can even set different priorities and weight for two records that are employed for the exact same service, but point to different servers for redundancy or load balancing. With an SRV record you can employ your domain address or a subdomain under it for a Voice-Over-IP server, for instance, and have the real software running on several machines with different providers. Which one a customer of yours will use will depend on the priority and weight values that you've set.