scaling vs size.

In the inspector tab, there’s scaling and size. When I change the size there’s hollow line indicated the size I am designating the cube, however the cube itself didn’t increase in size.
However, this is not the case when i am doing the same thing for terrain, when I change the size of the terrain it is actually changing the terrain’s size while scaling do nothing.

Can anyone explain this to me? Thanks

Normally, you don’t have scale and size, only scale.
Terrain is a special thing, you have to set terrain width and height, scale (and rotation) will be ignored.

If you are talking about a unity cube (Create → Cube), there is scale, this is the global scale for the cube.
“Size” is only for the collision box, which can be exactly as big as the cube (1,1,1) or bigger or smaller.

Green lines in the editor are indicating collision models (boxes, meshes, spheres…)