GivePulse objects: Users, Events, Impacts and Groups have default preset fields and parameters. e.g., the preset fields for the "User" object is: First Name, Last Name, DOB etc., for the "Event" object it is: Start Date, End Date, description etc.,
In the case you want to add custom fields to each of these objects, you can define unique fields or parameters that make the most sense for your group. e.g., if you wanted to add "Middle Name" Or "Occupation" Or "Work email" to the "User" object, you now have the ability to go into the settings page, specifically in the "Users" object and add custom fields. You can also do this via the "Manage Users" page under "Actions".