# Image and command

## `image`

A container image reference, for example `pytorch/pytorch:latest` or
`ghcr.io/acme/train:v4`. Use a tag or digest you control, so a restart after a
preemption runs the same code.

## `command`

What to run inside the container. Either a string, run through a shell, or a
list of arguments, run directly:

```python
command="python train.py --epochs 3"
command=["python", "train.py", "--epochs", "3"]
```

The list form avoids quoting problems and is recommended.

## Files

Write anything you want to keep under `/outputs`. See
[logs and outputs](/docs/guides/logs-and-outputs/).