Camera Manipulation Camera Focus/Subject

When doing camera manipulation, what is the difference between Camera.Focus and Camera.Subject

Subject is a part that the camera will constantly be attached to, and if the camera is set to a mode that isn’t scriptable, it will continue to follow that item until its subject changes or it is made Scriptable.

Focus is a CFrame, the Camera Focus is an area that the graphical engine will prioritise for rendering, I.E point lights around that centre will be rendered first etc.