# SRV

A Service Record (SRV record) is a specification of data in the [Domain Name System](/glossary/d/dns) containing information about [IP](/glossary/i/ip) and [port](/glossary/p/port) for a specific service.

It is used by domain servers to keep track of their own changes without having to contact a central DNS server.

An SRV record has the form:

`_Service._Proto.Name TTL Class SRV Priority Weight Port Target`

^ Item ^ Description ^
| Service | Identifier for the service. |
| Proto | The service protocol. |
| Name | Domain name where the record is valid. |
| TTL | DNS [time to live](/glossary/t/ttl). |
| Class | DNS class (IN for Internet). |
| Priority | Target host priority, lower value means more preferred. |
| Weight | A relative weight for records with the same priority. |
| Port | Port for the service. |
| Target | [Hostname](/glossary/h/hostname) for the service provider. |