Transform position reference

I do not seem to find this anywhere, but what exactly is the value of the position of an object? Suppose I have a cube, would the position be the middle of the cube? The topleft? The bottomleft? And how can I change the reference of the position to be the bottom left?

If you talk about the built-in default cube mesh than the mesh’s pivot is indeed in the center. So the vertex positions are defined at ± 0.5 units away from the origin. The built-in mesh is a fix mesh that can not be edited or changed in Unity. Unity is not a modelling software. However with Unity probuilder you can now create and edit simple meshes inside Unity.

However besides using probuilder you usually import your own assets which you may have created through other software (blender, maya, 3dsmax, …). If you’re not a 3d artist you could either try using pro builder as it’s quite simple or just parent the Unity default cube to an empty gameobject and offset the cube inside the empty gameobject by 0.5 in all axis. Now the origin of the parent is at the lower corner of the cube. Any further changes to the cube should be done to the newly created gameobject.