Choosing a door layout option:

A partial overlay reveals the cabinet's face frame. Typically in increments between .25"-.75"

A full overlay does not reveal the cabinet's face frame. The doors and or drawers are arranged so you see them side by side with enough gapping for the door and or drawer to operate.

Inset doors will show the entire face frame and create an opening slightly bigger than the door or drawer front to rest inside of. This style is most popular for built ins.

A popular option for bookcases is to have the shelves even with the perimeter frame of the bookcase. While this is a more "Appearance friendly" design it is a less cost effective approach. This is referred to as a flush face frame.

With inset bookcase shelving the shelves are "Set Back" from the face frame , typically around .5"