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# Name resolving
This examples shows how `ClientConn` can pick different name resolvers.
## What is a name resolver
A name resolver can be seen as a `map[service-name][]backend-ip`. It takes a
service name, and returns a list of IPs of the backends. A common used name
resolver is DNS.
In this example, a resolver is created to resolve `resolver.example.grpc.io` to
`localhost:50051`.
## Try it
```
go run server/main.go
```
```
go run client/main.go
```
## Explanation
The echo server is serving on ":50051". Two clients are created, one is dialing
to `passthrough:///localhost:50051`, while the other is dialing to
`example:///resolver.example.grpc.io`. Both of them can connect the server.
Name resolver is picked based on the `scheme` in the target string. See
https://github.com/grpc/grpc/blob/master/doc/naming.md for the target syntax.
The first client picks the `passthrough` resolver, which takes the input, and
use it as the backend addresses.
The second is connecting to service name `resolver.example.grpc.io`. Without a
proper name resolver, this would fail. In the example it picks the `example`
resolver that we installed. The `example` resolver can handle
`resolver.example.grpc.io` correctly by returning the backend address. So even
though the backend IP is not set when ClientConn is created, the connection will
be created to the correct backend.
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