When building an API, you may need a transformation layer that sits between your Eloquent models and the JSON responses that are actually returned to your application's users. Laravel's resource classes allow you to expressively and easily transform your models and model collections into JSON.
In other frameworks, they might be called transformers. Basically they are an array map of your model especially set up to be returned as JSON for an API.
I would say just give it a go and create one. The documentation has pretty clear examples as well.