In the context of building a charm, in Rockcraft and Charmcraft, a profile is a name you can pass as an argument during rock / charm initialisation that will create all the usual rock/charm project files in a form customised for a specific purpose – i.e., for a Kubernetes charm, for a Kubernetes charm for a Flask application etc. – in order to speed up development.
The customisation often takes the shape of a specific extension in the charm’s charmcraft.yaml file.
See more: How to set up a charm project