Profile types

GenericSetup has two kinds of profiles that you can create. A base profile is a profile that defines the basis for the site configuration.  In Plone the base profile is the "plone" profile from the CMFPlone product. A base profile is not typically something that product developers needs to deal with.  There can only be one base profile in use, when you create a new Plone site the base profile is applied for you.  The base profile will setup a default set of import and export steps along with a default configuration for each.

The second type of profile is an extension profile. An extension profile is what allows us to build on top of the base profile. When you create a new product, theme or policy package you will register extension profiles to build on top of the existing configuration. Extension profiles also allow you to define new import and export steps that other extension profiles can use.