AutoCad :: Grid / Limits And Model Space Area - Drawing Scale

What is the advantage/usage of limits command? I know it specify the area where could be filled with Grid command. But is it, its only usage? What other usage could be expected from "limits"?

If we want to make the paper space and model space same (draw in same scale, if we use 1/100 scale in metric system, 1 meter in model space is equal to 1 centimeter in paper space), is it a wise idea to set the model space into A4 or A3 paper size by use of LIMITS?

I think its utmost usage is in combination with "snap". Where you can quickly grab the points you want onscreen without need for coordinate input. Would be happy if there is other usage for GRID

Before, I thought limits will specify the area in model space where I can draw (limit the area of model space). But this is in contrary with the fact that model space is limitless and I can draw as far as I want.

It is really hard to understand that there is no limit for model space like real world.

I haven't understood these issues until I read many threads in CT. Now I have got most of them but I think I need some extra study to understand them 100%.