Laptops with a dedicated graphics card

A friend of mine has just bought a laptop with Windows 10 and a dedicated graphics card. I am attaching a few screenshots below so that I can ask you a few questions.1. In PCs a dedicated graphics card is a totally separate piece of hardware, but what about laptops with a dedicated graphics card? Is there a separate chip altogether?2. In the two screenshots, which show a window titled "DirectX Diagnostic Tool", I see something called "Shared Memory: 4017 MB". I know this laptop has 8 GB DDR4 RAM. In my understanding 8 GB means 8192 MB. So why the shared memory is shown as 4017 MB only? Is this shared memory not system memory itself?3. One screenshot also shows "Display memory (VRAM): 2996 MB". Is this the memory of that dedicated graphics card/chip? If divided by 1024 MB it works out to about 2.92 GB.4. I need someone to explain to me as to how one can work out memory math when it comes to a laptop with a dedicated graphics card.Thanks.

Imgur: The magic of the Internet

Yes, there is a separate chip if you have iGPU and dedicated GPU in a laptop.
Shared Memory as far as I know is a system memory (RAM) that can be use by the GPU, so it can only use as much as 4GB of your system memory.
The laptop has a GTX 1050 and the dedicated VRAM of this GPU is 2.9GB or usually just called 3GB.
In my understanding the GPU will only use the dedicated VRAM which is 2.9GB unless you're exceeding that limit, then the GPU will use your system memory which is limited to 4GB of shared memory.

thanks a lot sir

In practice the limit is really 3 GB (VRAM) as the (potential) shared memory is never used as far as I can tell. Presumably because games are written for Desktop Graphics cards. Mobile graphics chips are not supported, though they do work.

In several games where there is a VRAM indicator in game settings it will probably go red above 3 GB. That is for them to experiment.

In Display 1, the integrated GPU Intel UHD 630 can use up to half the installed RAM 4 GB of 8 GB.

I have never seen on mine any application/game using the Nvidia dedicated GPU use above 2 GB of VRAM. i.e. dipping into the shared RAM allocation.