What does component part of a building mean? Colums , beams etc or floor windows etc?
Or does it include both?

Commonly foundation,column,beam walls and roof are called part of buildings.
But we have to check who is using these terms and why. For example for a seller of building material ,whatever is used in building is part of building.But for structural designer only designing components will be part of the building.

Building parts:
p.c.c.
Brickwork in substructure
r.c.c. in foundation(for frame structure building)
Plinth beam
d.p.c.
Brickwork in superstructure
Lintal
r.c.c slab & beam
Flooring
Plastering
Pointing
Painting
Terracing
Parapet wall
Coping
Gola

1 foundation
2 plinth
3 walls & columns
4 floors
5 lintels & chajjas
6 roof
7 doors & windows
8 stair & lift
9 finishing work
10 building services
11 fencing and external work