Forms
A form is a layout for entering or updating items. Say which roles can use it in which states. Each role that can create items has one default create form.
When a role opens a form, fields it may only see are read-only, and hidden fields simply aren't there.
The All fields form, with every field, is kept up to date for you and can't be deleted.
Use the generator to make a starting form, then arrange it in the designer.
Grids
A grid is a named set of columns for listing items: one per stage, say, or one per team. Say which roles use each. Each grid has its own colour so people can tell them apart.
Forms and grids are shown as cards. Open one to edit it; ← All forms (or All grids) takes you back.