[Lhotch]

There are certain predefined fields such as username city, state, address, country, phone etc etc. This can be selectivly displayed or hidden via admin.

Next you can add extra fields (text fields, drop down lists, check boxes etc) from within admin. When creating these fields you also specify what category these fields are linked to. So if your site sells boats and houses you may want make, model, year fields that appear only for the boat categorey and for the house category you can have different fields for sqaure footage etc etc.

The countries and states can be editied within admin and are stored in the database.