SRV, which is an abbreviation for Service, is a DNS record, which enables you to employ a domain for a specific service different from a site. By creating a few SRV records, you’re able to use the domain name with different providers and direct it to numerous servers at once, every single server managing a different service. You can specify the port number for the connection to every single machine, so there won't be any interference. You could also set individual priorities and weight for 2 records that are used for the exact same service, but forward to different servers for redundancy or load balancing. Using an SRV record you can use your domain address or a subdomain under it for a Voice-Over-IP server, for example, and have the real software running on various machines with different providers. Which one a client of yours is going to use is determined by the priority and weight values you have set.