====

Use a contextual binding in the service container to inject different implementations of the same interface into different classes. For example, in a service provider’s `register()` method you can do:

```php
$this->app->when(ReportController::class)
          ->needs(DataExporter::class)
          ->give(CsvExporter::class);

$this->app->when(BackupController::class)
          ->needs(DataExporter::class)
          ->give(ZipExporter::class);
```

Now both controllers type‐hint `DataExporter` in their constructors, but get completely different concrete exporters—making your code far more flexible and testable.