hraza1335 :
So plz tell me overall direct to the point, it means we can use system Ram to help increase VRam, Right??
Yes and no: yes, the GPU can borrow system RAM to handle larger workloads than what its local frame buffer can handle. However, this comes at a potentially massive performance loss due to much lower bandwidth and much higher latency. You may have tons of GPU-power available but large chunks of it become untappable because they're starving on RAM/VRAM.
This is a lot like using a swapfile when you run out of system RAM. It stops the OS from outright crashing programs when they try to allocate more RAM than what is physically available at the expense of a massive (50-99%) performance loss when this happens too often.
Short version: it works but ain't no substitute.