There are three basic cabinet door types. Choose your cabinet hinge according to the cabinet's door type.
Overlay Door - The back of the cabinet door is flat and it overlays the frame. The overlay can have a specific measurement, 1/2" as shown, or variable.
Inset / Door -
Part of the cabinet door overlays into the frame and has a recess/ rabbet cut on the back, usually 3/8" by 3/8". When the cabinet door is closed, the frame wing is visible but the door wing is concealed.
FlushDoor - The cabinet door is inset into the frame so the door and frame are flush with each other. The knuckle of the hinge is exposed, but both wings of the hinge are concealed.