ibsys wrote:
can somebody explain please what "solid core wood door" is?
is it a door made of wood?

Sorry for such a novice question.

Solid = no air spaces. From front to back, you get wood.

Not Solid = a frame with wood veneer on each side. It's hollow.

Not Solid also is cheaper and used, mostly, for interior doors. Solid doors
are sturdier and stronger (and much heavier) and are used (mostly) for door
that open to the outside.

A compromise is a steel-clad door. It's hollow, but the facings of steel are
hardier than the wood veneer.