Since you prefer "the gist" I'll try to be general here:
Fi - concern and passion for things of value, things that are "worth believing in". It has a very strong self-created internal sense of values, which feeds its need for moral and ethical definition.
Fe - (for the sake of contrast) - concern and awareness for others' feelings in a community or group. It has a deep need for external validation, and thus often talks about its feelings, whether everyone else wants to hear it or not.
(Fe typically gets hurt by others' behavior or words, Fi typically gets hurt by the cruelty of the world it lives in.)
Hope this helps