Grouping
When you use multiple cameras in the same scene you can restrict which objects are seen on which camera.
Camera has a Visibility Group property that designates which group of objects it renders.
The objects' Grouping property specifies which groups they belong to.  For e.g  0, 1, 1, 0, 0 specifies that the object is visible in groups 2, 3, but not in groups  1, 4, 5.
By default all objects are visible in all groups.

Index
It can only be used with instancing and in very special cases, just ignore it.

Force Visible
Normally objects that are outside of the camera view frustum are not rendered for optimization purposes. In some very special cases you might need to force rendering an object even if it's not visible.

Force Distance
Transparent objects are rendered in order based on their center's distance from the camera to ensure the right covering. (Opaque object covering is determined correctly pixel-by-pixel using a depth map, but this method cannot be used with transparent objects.) But some cases this ordering is not correct. For e.g. you have an U-shaped glass and you put another small glass object in front of it. In this case the system will sense the small object as the farther one. One solution is to slice up the U-shaped object into multiple pieces.  But if you do not want to do that you can set Force Distance that will overwrite the distance value automatically calculated by the system. For e.g. you set it to 1000 for the U-shaped object that will result in rendering it first.

Build Factor
It determines how much portion of the object is rendered. For e.g. 0.5 means only the first half of its polygons are rendered. If you animate it you can get a rudimentary "build-up" effect of the object.

Vertex Color
If you use a shader that supports vertex color by default it will use vertex color data from the model if any. But in addition you can modulate the color of the vertices by this property. It has no effect on shaders that do not support vertex color.

Shader Index
Instead of a single shader you can also connect a Shader Array to an object.

In this case Shader Index can be used to switch between the shaders.
By default it's 0 which means that the Camera's gobal Shader Index property is applied.
Camera also has a separate Cond Shader Index. It is a conditionally used index: for e.g. if it's 3 then if any object that has a Shader 3 via a Shader Array it will be used, but if not the object will use the normal Shader Index.
For e.g Render_General.xcomp (which is recommended when you build a virtual scene from scratch), use Cond Shader Index = 8 for the Mirror Camera. It means that you can use different shader for an object itself and for its reflected image. This trick is used with billboards for e.g.

thank you for these answers