Groovy's convention for properties is that any field without any visibility modifier is exposed as a property, with a getter and a setter transparently generated for you. For instance, this Person class exposes a getter getName() and a setter setName() for a private name field:
Which is equivalent to this Java class:
That said, this approach has one drawback in that you don't have the possibility to define a field with package-scope visibility. To be able to expose a field with package-scope visibility, you can now annotate your field with the @PackageScope annotation.