# What Is the Difference between Docker-Compose Ports and Expose?

You may have wondered what is the difference between docker-compose ports and docker-compose expose. Here is a clear explanation to help you better understand the matter.

## Ports

**Ports** mentioned in the `docker-compose.yml` file will be shared among different services started by the `docker-compose.yml`. These ports will be then exposed to the host to a random port or predefined port.

This configuration will set the port to `3306` for the services and then expose this port to the host as port `32769` (this port will be chosen randomly)

```bash
mysql:
  image: mysql:5.7
  ports:
    - "3306"
```

```bash
docker-compose ps
Output:
Name                     Command               State            Ports
-------------------------------------------------------------------------------------
  mysql_1       docker-entrypoint.sh mysqld      Up      0.0.0.0:32769->3306/tcp
```

## Expose

On the other hand, **expose** ports mentioned in the docker-compose.yml file will be only accessible to linked services and won’t be exposed to the host.

The following example will set the expose the port `3306` only to the connected services and won't expose the port to the host:

```bash
mysql:
  image: mysql:5.7
  expose:
    - "3306"
```

```bash
docker-compose ps
Output:
Name                  Command             State    Ports
---------------------------------------------------------------
 mysql_1      docker-entrypoint.sh mysqld   Up      3306/tcp
```