Btw, it really help once I figured out the difference between base, case and crown molding.
Casing is a type of molding, typically used to trim the perimeter of windows and doors. Casing is typically less wide (tall?), but thicker than base molding.
Base molding (or baseboard) is a type of molding, which is applied where the wall and floor meet.
Crown molding (or crowns) is a type of molding, which is applied where the wall and ceiling meet.