A variables file contains variable definitions that may be used as the context for parsing a [steps file](steps-file.md) *before* the actual commands are generated.
As seen in the example above, the value is defined by simply adding a variable parameter:
```ini
[domain_name]
value: example.com
[database_host]
value: db1.example.com
```
!!! note
This is the minimum definition for all variables.
## Defining An Environment
You may define an environment for any given variable that may be used for filtering variables. This is done by adding the environment name to the variable name:
```ini
[database_host:development]
value: localhost
[database_host:live]
value: db1.example.com
```
In this way, variables of the same name may be supported across different deployment environments.
## Adding Comments
As demonstrated in the example above, you may comment on a variable by adding a `comment:` attribute to the section.