solid core wood door
 

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

Sorry for such a novice question.

A solid wood door is what all doors were 100 years ago--solid wood. Most interior doors today have a hollow core. They are made with a narrow perimiter of solid wood and solid wood in the area of the handle and lock. They are finished with a thin layer of veneer for the surface.